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Amine | From alkenes | From alkenes
Disubstituted alkenes react with HCN in the presence of strong acids to give formamides, which can be decarbonylated. This method, the Ritter reaction, is used industrially to produce tertiary amines such as tert-octylamine.
Hydroamination of alkenes is also widely practiced. The reaction is catalyzed by zeolite-based solid acids. |
Amine | Reductive routes | Reductive routes
Via the process of hydrogenation, unsaturated N-containing functional groups are reduced to amines using hydrogen in the presence of a nickel catalyst. Suitable groups include nitriles, azides, imines including oximes, amides, and nitro. In the case of nitriles, reactions are sensitive to acidic or alkaline conditions, which can cause hydrolysis of the group. is more commonly employed for the reduction of these same groups on the laboratory scale.
Many amines are produced from aldehydes and ketones via reductive amination, which can either proceed catalytically or stoichiometrically.
Aniline () and its derivatives are prepared by reduction of the nitroaromatics. In industry, hydrogen is the preferred reductant, whereas, in the laboratory, tin and iron are often employed. |
Amine | Specialized methods | Specialized methods
Many methods exist for the preparation of amines, many of these methods being rather specialized.
Reaction name Substrate Comment Staudinger reductionOrganic azide This reaction also takes place with a reducing agent such as lithium aluminium hydride. Schmidt reactionCarboxylic acid Aza-Baylis–Hillman reactionImine Synthesis of allylic amines Birch reduction Imine Useful for reactions that trap unstable imine intermediates, such as Grignard reactions with nitriles. Hofmann degradationAmide This reaction is valid for preparation of primary amines only. Gives good yields of primary amines uncontaminated with other amines. Hofmann elimination Quaternary ammonium saltUpon treatment with strong base Leuckart reaction Ketones and aldehydes Reductive amination with formic acid and ammonia via an imine intermediate Hofmann–Löffler reaction Haloamine Eschweiler–Clarke reaction Amine Reductive amination with formic acid and formaldehyde via an imine intermediate |
Amine | Reactions | Reactions |
Amine | Alkylation, acylation, and sulfonation, etc. | Alkylation, acylation, and sulfonation, etc.
Aside from their basicity, the dominant reactivity of amines is their nucleophilicity. Most primary amines are good ligands for metal ions to give coordination complexes. Amines are alkylated by alkyl halides. Acyl chlorides and acid anhydrides react with primary and secondary amines to form amides (the "Schotten–Baumann reaction").
center|Amide formation
Similarly, with sulfonyl chlorides, one obtains sulfonamides. This transformation, known as the Hinsberg reaction, is a chemical test for the presence of amines.
Because amines are basic, they neutralize acids to form the corresponding ammonium salts . When formed from carboxylic acids and primary and secondary amines, these salts thermally dehydrate to form the corresponding amides.
Amines undergo sulfamation upon treatment with sulfur trioxide or sources thereof:
R2NH + SO3 -> R2NSO3H |
Amine | Diazotization | Diazotization
Amines reacts with nitrous acid to give diazonium salts. The alkyl diazonium salts are of little importance because they are too unstable. The most important members are derivatives of aromatic amines such as aniline ("phenylamine") (A = aryl or naphthyl):
ANH2 + HNO2 + HX -> AN2+ + X- + 2 H2O
Anilines and naphthylamines form more stable diazonium salts, which can be isolated in the crystalline form. Diazonium salts undergo a variety of useful transformations involving replacement of the group with anions. For example, cuprous cyanide gives the corresponding nitriles:
AN2+ + Y- -> AY + N2
Aryldiazoniums couple with electron-rich aromatic compounds such as a phenol to form azo compounds. Such reactions are widely applied to the production of dyes. |
Amine | Conversion to imines | Conversion to imines
Imine formation is an important reaction. Primary amines react with ketones and aldehydes to form imines. In the case of formaldehyde (R' H), these products typically exist as cyclic trimers: RNH2 + R'_2C=O -> R'_2C=NR + H2O Reduction of these imines gives secondary amines: R'_2C=NR + H2 -> R'_2CH-NHR
Similarly, secondary amines react with ketones and aldehydes to form enamines: R2NH + R'(R''CH2)C=O -> R''CH=C(NR2)R' + H2O
Mercuric ions reversibly oxidize tertiary amines with an α hydrogen to iminium ions: Hg^2+ + R2NCH2R' <=> Hg + [R2N=CHR']+ + H+ |
Amine | Overview | Overview
An overview of the reactions of amines is given below:
Reaction name Reaction product Comment Amine alkylationAmines Degree of substitution increases Schotten–Baumann reactionAmide Reagents: acyl chlorides, acid anhydrides Hinsberg reactionSulfonamides Reagents: sulfonyl chlorides Amine–carbonyl condensationImines Organic oxidationNitroso compounds Reagent: peroxymonosulfuric acid Organic oxidation Diazonium salt Reagent: nitrous acid Zincke reactionZincke aldehyde Reagent: pyridinium salts, with primary and secondary amines Emde degradationTertiary amine Reduction of quaternary ammonium cations Hofmann–Martius rearrangementAryl-substituted anilines von Braun reaction Organic cyanamideBy cleavage (tertiary amines only) with cyanogen bromide Hofmann elimination AlkeneProceeds by β-elimination of less hindered carbon Cope reaction AlkeneSimilar to Hofmann elimination Carbylamine reaction IsonitrilePrimary amines only Hofmann's mustard oil test IsothiocyanateCarbon disulfide and mercury(II) chloride are used. Thiocyanate smells like mustard. |
Amine | Biological activity | Biological activity
Amines are ubiquitous in biology. The breakdown of amino acids releases amines, famously in the case of decaying fish which smell of trimethylamine. Many neurotransmitters are amines, including epinephrine, norepinephrine, dopamine, serotonin, and histamine. Protonated amino groups () are the most common positively charged moieties in proteins, specifically in the amino acid lysine. The anionic polymer DNA is typically bound to various amine-rich proteins. Additionally, the terminal charged primary ammonium on lysine forms salt bridges with carboxylate groups of other amino acids in polypeptides, which is one of the primary influences on the three-dimensional structures of proteins. |
Amine | Amine hormones | Amine hormones
Hormones derived from the modification of amino acids are referred to as amine hormones. Typically, the original structure of the amino acid is modified such that a –COOH, or carboxyl, group is removed, whereas the , or amine, group remains. Amine hormones are synthesized from the amino acids tryptophan or tyrosine. |
Amine | Application of amines | Application of amines |
Amine | Dyes | Dyes
Primary aromatic amines are used as a starting material for the manufacture of azo dyes. It reacts with nitrous acid to form diazonium salt, which can undergo coupling reaction to form an azo compound. As azo-compounds are highly coloured, they are widely used in dyeing industries, such as:
Methyl orange
Direct brown 138
Sunset yellow FCF
Ponceau |
Amine | Drugs | Drugs
Most drugs and drug candidates contain amine functional groups:
Chlorpheniramine is an antihistamine that helps to relieve allergic disorders due to cold, hay fever, itchy skin, insect bites and stings.
Chlorpromazine is a tranquilizer that sedates without inducing sleep. It is used to relieve anxiety, excitement, restlessness or even mental disorder.
Ephedrine and phenylephrine, as amine hydrochlorides, are used as decongestants.
Amphetamine, methamphetamine, and methcathinone are psychostimulant amines that are listed as controlled substances by the US DEA.
Thioridazine, an antipsychotic drug, is an amine which is believed to exhibit its antipsychotic effects, in part, due to its effects on other amines.American Society of Health System Pharmacists; AHFS Drug Information 2010. Bethesda, MD. (2010), p. 2510
Amitriptyline, imipramine, lofepramine and clomipramine are tricyclic antidepressants and tertiary amines.
Nortriptyline, desipramine, and amoxapine are tricyclic antidepressants and secondary amines. (The tricyclics are grouped by the nature of the final amino group on the side chain.)
Substituted tryptamines and phenethylamines are key basic structures for a large variety of psychedelic drugs.
Opiate analgesics such as morphine, codeine, and heroin are tertiary amines. |
Amine | Gas treatment | Gas treatment
Aqueous monoethanolamine (MEA), diglycolamine (DGA), diethanolamine (DEA), diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) are widely used industrially for removing carbon dioxide (CO2) and hydrogen sulfide (H2S) from natural gas and refinery process streams. They may also be used to remove CO2 from combustion gases and flue gases and may have potential for abatement of greenhouse gases. Related processes are known as sweetening. |
Amine | Epoxy resin curing agents | Epoxy resin curing agents
Amines are often used as epoxy resin curing agents. These include dimethylethylamine, cyclohexylamine, and a variety of diamines such as 4,4-diaminodicyclohexylmethane. Multifunctional amines such as tetraethylenepentamine and triethylenetetramine are also widely used in this capacity. The reaction proceeds by the lone pair of electrons on the amine nitrogen attacking the outermost carbon on the oxirane ring of the epoxy resin. This relieves ring strain on the epoxide and is the driving force of the reaction.Howarth G.A "Synthesis of a legislation compliant corrosion protection coating system based on urethane, oxazolidine and waterborne epoxy technology" pages 12, Chapter 1.3.1 Master of Science Thesis April 1997 Imperial College London Molecules with tertiary amine functionality are often used to accelerate the epoxy-amine curing reaction and include substances such as 2,4,6-Tris(dimethylaminomethyl)phenol. It has been stated that this is the most widely used room temperature accelerator for two-component epoxy resin systems. |
Amine | Safety | Safety
Low molecular weight simple amines, such as ethylamine, are toxic with between 100 and 1000 mg/kg. They are skin irritants, especially as some are easily absorbed through the skin. Amines are a broad class of compounds, and more complex members of the class can be extremely bioactive, for example strychnine. |
Amine | See also | See also
Acid–base extraction
Amine value
Amine gas treating
Ammine
Biogenic amine
Ligand isomerism
Official naming rules for amines as determined by the International Union of Pure and Applied Chemistry (IUPAC) |
Amine | References | References |
Amine | Further reading | Further reading
|
Amine | External links | External links
Synthesis of amines
Factsheet, amines in food
Category:Functional groups |
Amine | Table of Content | Short description, Classification of amines, Naming conventions, Physical properties, Spectroscopic identification, Structure, Alkyl amines, Aromatic amines, Basicity, Electronic effects, Solvation effects, Synthesis, From alcohols, From alkyl and aryl halides, From alkenes, Reductive routes, Specialized methods, Reactions, Alkylation, acylation, and sulfonation, etc., Diazotization, Conversion to imines, Overview, Biological activity, Amine hormones, Application of amines, Dyes, Drugs, Gas treatment, Epoxy resin curing agents, Safety, See also, References, Further reading, External links |
April 29 | pp-move | |
April 29 | Events | Events |
April 29 | Pre-1600 | Pre-1600
801 – An earthquake in the Central Apennines hits Rome and Spoleto, damaging the basilica of San Paolo Fuori le Mura.
1091 – Battle of Levounion: The Pechenegs are defeated by Byzantine Emperor Alexios I Komnenos.
1429 – Joan of Arc arrives to relieve the Siege of Orléans.
1483 – Gran Canaria, the main island of the Canary Islands, is conquered by the Kingdom of Castile.
1521 – Swedish War of Liberation: Swedish troops defeat a Danish force in the Battle of Västerås. |
April 29 | 1601–1900 | 1601–1900
1760 – French forces commence the siege of Quebec which is held by the British.
1770 – James Cook arrives in Australia at Botany Bay, which he names.
1781 – American Revolutionary War: British and French ships clash in the Battle of Fort Royal off the coast of Martinique.
1826 – The galaxy Centaurus A or NGC 5128 is discovered by James Dunlop. Centaurus A is listed on p. 138 as entry number 482. A sketch of Centaurus A appears as Fig. 20 on the plate between pages 114 and 115.
1861 – Maryland in the American Civil War: Maryland's House of Delegates votes not to secede from the Union.
1862 – American Civil War: The Capture of New Orleans by Union forces under David Farragut.
1864 – Theta Xi fraternity is founded at Rensselaer Polytechnic Institute, the only fraternity to be founded during the American Civil War.; |
April 29 | 1901–present | 1901–present
1903 – A landslide kills 70 people in Frank, in the District of Alberta, Canada.
1910 – The Parliament of the United Kingdom passes the People's Budget, the first budget in British history with the expressed intent of redistributing wealth among the British public.
1911 – Tsinghua University, one of mainland China's leading universities, is founded.
1916 – World War I: The UK's 6th Indian Division surrenders to Ottoman Forces at the Siege of Kut in one of the largest surrenders of British forces up to that point.
1916 – Easter Rising: After six days of fighting, Irish rebel leaders surrender to British forces in Dublin, bringing the Easter Rising to an end.
1945 – World War II: The Surrender of Caserta is signed by the commander of German forces in Italy.
1945 – World War II: Airdrops of food begin over German-occupied regions of the Netherlands.
1945 – World War II: Adolf Hitler marries his longtime partner Eva Braun in a Berlin bunker and designates Admiral Karl Dönitz as his successor.
1945 – Dachau concentration camp is liberated by United States troops.
1946 – The International Military Tribunal for the Far East convenes and indicts former Prime Minister of Japan Hideki Tojo and 28 former Japanese leaders for war crimes.
1952 – Pan Am Flight 202 crashes into the Amazon basin near Carolina, Maranhão, Brazil, killing 50 people.
1953 – The first U.S. experimental 3D television broadcast shows an episode of Space Patrol on Los Angeles ABC affiliate KECA-TV.
1967 – After refusing induction into the United States Army the previous day, Muhammad Ali is stripped of his boxing title.
1970 – Vietnam War: United States and South Vietnamese forces invade Cambodia to interdict the Ho Chi Minh Trail in an attempt to cut off supplies to the Viet Cong and the North Vietnamese Army.
1974 – Watergate scandal: United States President Richard Nixon announces the release of edited transcripts of White House tape recordings relating to the scandal.
1975 – Vietnam War: Operation Frequent Wind: The U.S. begins to evacuate U.S. citizens from Saigon before an expected North Vietnamese takeover. U.S. involvement in the war comes to an end. This happens after the bombing of Bombing of Tan Son Nhut Air Base.
1975 – Vietnam War: The North Vietnamese Army completes its capture of all parts of South Vietnam-held Trường Sa Islands.
1985 – Space Shuttle Challenger is launched on STS-51-B.
1986 – A fire at the Central library of the Los Angeles Public Library damages or destroys 400,000 books and other items.
1986 – The United States Navy aircraft carrier becomes the first nuclear-powered aircraft carrier to transit the Suez Canal, navigating from the Red Sea to the Mediterranean Sea to relieve the .
1986 – An assembly of Sikhs, known as a Sarbat Khalsa, officially declared independence for a state of Khalistan.
1991 – A cyclone strikes the Chittagong district of southeastern Bangladesh with winds of around , killing at least 138,000 people and leaving as many as ten million homeless.
1991 – The 7.0 Racha earthquake affects Georgia with a maximum MSK intensity of IX (Destructive), killing 270 people.
1992 – Riots in Los Angeles begin, following the acquittal of police officers charged with excessive force in the beating of Rodney King. Over the next three days 63 people are killed and hundreds of buildings are destroyed.
1997 – The Chemical Weapons Convention of 1993 enters into force, outlawing the production, stockpiling and use of chemical weapons by its signatories.
2004 – The final Oldsmobile is built in Lansing, Michigan, ending 107 years of vehicle production.
2011 – The Wedding of Prince William and Catherine Middleton takes place at Westminster Abbey in London.
2013 – A powerful explosion occurs in an office building in Prague, believed to have been caused by natural gas, and injures 43 people.
2013 – National Airlines Flight 102, a Boeing 747-400 freighter aircraft, crashes during takeoff from Bagram Airfield in Parwan Province, Afghanistan, killing all seven people on board.
2015 – A baseball game between the Baltimore Orioles and the Chicago White Sox sets the all-time low attendance mark for Major League Baseball. Zero fans were in attendance for the game, as the stadium was officially closed to the public due to the 2015 Baltimore protests. |
April 29 | Births | Births |
April 29 | Pre-1600 | Pre-1600
1469 – William II, Landgrave of Hesse (d. 1509)
1587 – Sophie of Saxony, Duchess of Pomerania (d. 1635) |
April 29 | 1601–1900 | 1601–1900
1636 – Esaias Reusner, German lute player and composer (d. 1679)
1665 – James Butler, 2nd Duke of Ormonde, Irish general and politician, Lord Lieutenant of Ireland (d. 1745)
1667 – John Arbuthnot, Scottish-English physician and polymath (d. 1735)
1727 – Jean-Georges Noverre, French actor and dancer (d. 1810)
1745 – Oliver Ellsworth, American lawyer and politician, 3rd Chief Justice of the United States (d. 1807)
1758 – Georg Carl von Döbeln, Swedish general (d. 1820)
1762 – Jean-Baptiste Jourdan, French general and politician, French Minister of Foreign Affairs (d. 1833)
1780 – Charles Nodier, French librarian and author (d. 1844)
1783 – David Cox, English landscape painter (d. 1859)
1784 – Samuel Turell Armstrong, American publisher and politician, 14th Lieutenant Governor of Massachusetts (d. 1850)
1810 – Thomas Adolphus Trollope, English journalist and author (d. 1892)
1818 – Alexander II of Russia (d. 1881)
1837 – Georges Ernest Boulanger, French general and politician, French Minister of War (d. 1891)
1842 – Carl Millöcker, Austrian composer and conductor (d. 1899)
1847 – Joachim Andersen, Danish flautist, composer and conductor (d. 1907)
1848 – Raja Ravi Varma, Indian painter and academic (d. 1906)
1854 – Henri Poincaré, French mathematician, physicist and engineer (d. 1912)
1863 – Constantine P. Cavafy, Egyptian-Greek journalist and poet (d. 1933)
1863 – William Randolph Hearst, American publisher and politician, founded the Hearst Corporation (d. 1951)
1863 – Maria Teresia Ledóchowska, Austrian nun and missionary (d. 1922)
1872 – Harry Payne Whitney, American businessman and lawyer (d. 1930)
1872 – Forest Ray Moulton, American astronomer and academic (d. 1952)
1875 – Rafael Sabatini, Italian-English novelist and short story writer (d. 1950)
1879 – Thomas Beecham, English conductor (d. 1961)
1880 – Adolf Chybiński, Polish historian, musicologist and academic (d. 1952)
1882 – Auguste Herbin, French painter (d. 1960)
1882 – Hendrik Nicolaas Werkman, Dutch printer, typographer, and Nazi resister (d. 1945)
1885 – Egon Erwin Kisch, Czech journalist and author (d. 1948)
1887 – Robert Cushman Murphy, American ornithologist (d. 1973)
1888 – Michael Heidelberger, American immunologist (d. 1991)
1891 – Edward Wilfred Taylor, British businessman (d. 1980)
1893 – Harold Urey, American chemist and astronomer, Nobel Prize laureate (d. 1981)
1894 – Marietta Blau, Austrian physicist and academic (d. 1970)
1895 – Vladimir Propp, Russian scholar and critic (d. 1970)
1895 – Malcolm Sargent, English organist, composer and conductor (d. 1967)
1898 – E. J. Bowen, British physical chemist (d. 1980)
1899 – Duke Ellington, American pianist, composer and bandleader (d. 1974)
1899 – Mary Petty, American illustrator (d. 1976)
1900 – Amelia Best, Australian politician (d. 1979) |
April 29 | 1901–present | 1901–present
1901 – Hirohito, Japanese emperor (d. 1989)
1907 – Fred Zinnemann, Austrian-American director and producer (d. 1997)
1908 – Jack Williamson, American author and academic (d. 2006)
1909 – Tom Ewell, American actor (d. 1994)
1912 – Richard Carlson, American actor, director, and screenwriter (d. 1977)
1915 – Henry H. Barschall, German-American physicist and academic (d. 1997)
1917 – Maya Deren, Ukrainian-American director, poet, and photographer (d. 1961)
1917 – Celeste Holm, American actress and singer (d. 2012)
1918 – George Allen, American football player and coach (d. 1990)
1919 – Gérard Oury, French actor, director and screenwriter (d. 2006)
1920 – Edward Blishen, English author and radio host (d. 1996)
1920 – Harold Shapero, American composer (d. 2013)
1922 – Parren Mitchell, American politician (d. 2007)
1922 – Toots Thielemans, Belgian guitarist and harmonica player (d. 2016)
1923 – Irvin Kershner, American actor, director and producer (d. 2010)
1924 – Zizi Jeanmaire, French ballerina and actress (d. 2020)
1925 – John Compton, Saint Lucian lawyer and politician, 1st Prime Minister of Saint Lucia (d. 2007)
1925 – Iwao Takamoto, American animator, director, and producer (d. 2007)
1926 – Elmer Kelton, American journalist and author (d. 2009)
1927 – Dorothy Manley, English sprinter (d. 2021)
1927 – Bill Slater, English footballer (d. 2018)
1928 – Carl Gardner, American singer (d. 2011)
1928 – Heinz Wolff, German-English physiologist, engineer, and academic (d. 2017)
1929 – Walter Kempowski, German author and academic (d. 2007)
1929 – Peter Sculthorpe, Australian composer and conductor (d. 2014)
1929 – April Stevens, American singer (d. 2023)
1929 – Maurice Strong, Canadian businessman and diplomat (d. 2015)
1929 – Jeremy Thorpe, English lawyer and politician (d. 2014)
1930 – Jean Rochefort, French actor and director (d. 2017)
1931 – Frank Auerbach, German-British painter (d. 2024)
1931 – Lonnie Donegan, Scottish-English singer-songwriter and guitarist (d. 2002)
1931 – Chris Pearson, Canadian politician, 1st Premier of Yukon (d. 2014)
1932 – David Tindle, English painter and educator
1932 – Dmitry Zaikin, Soviet pilot and cosmonaut instructor (d. 2013)
1933 – Ed Charles, American baseball player and coach (d. 2018)
1933 – Rod McKuen, American singer-songwriter and poet (d. 2015)
1933 – Willie Nelson, American singer-songwriter, guitarist, producer and actor
1934 – Luis Aparicio, Venezuelan-American baseball player
1934 – Pedro Pires, Cape Verdean politician, 3rd President of Cape Verde
1935 – Otis Rush, American blues singer-songwriter and guitarist (d. 2018)
1936 – Zubin Mehta, Indian conductor
1936 – Adolfo Nicolás, Spanish priest, 13th Superior General of the Society of Jesus (d. 2020)
1936 – Alejandra Pizarnik, Argentine poet (d. 1972)
1936 – Jacob Rothschild, 4th Baron Rothschild, English banker and philanthropist (d. 2024)
1937 – Jill Paton Walsh, English author (d. 2020)
1938 – Steven Bach, American writer, businessman and educator (d. 2009)
1938 – Bernie Madoff, American businessman, financier and convicted felon (d. 2021)
1939 – Klaus Rinke, German contemporary artist
1940 – George Adams, American musician (d. 1992)
1940 – Peter Diamond, American economist
1941 – Hanne Darboven, German painter (d. 2009)
1942 – Dick Chrysler, American politician
1942 – Rennie Fritchie, Baroness Fritchie, English civil servant and academic
1943 – Duane Allen, American country singer
1943 – Brenda Dean, Baroness Dean of Thornton-le-Fylde, English union leader and politician (d. 2018)
1943 – Ruth Deech, Baroness Deech, English lawyer and academic
1944 – Francis Lee, English footballer and businessman (d. 2023)
1945 – Hugh Hopper, English bass guitarist (d. 2009)
1945 – Catherine Lara, French singer-songwriter and violinist
1945 – Tammi Terrell, American soul singer-songwriter (d. 1970)
1946 – Rodney Frelinghuysen, American politician and lobbyist
1947 – Tommy James, American singer-songwriter, guitarist and producer
1947 – Johnny Miller, American golfer and sportscaster
1947 – Jim Ryun, American runner and politician
1948 – Edith Brown Clement, American judge
1950 – Paul Holmes, New Zealand journalist (d. 2013)
1950 – Phillip Noyce, Australian director and producer
1950 – Debbie Stabenow, American social worker and politician
1951 – Dale Earnhardt, American race car driver (d. 2001)
1951 – Jon Stanhope, Australian politician
1952 – Geraldine Doogue, Australian journalist and television host
1952 – Nora Dunn, American actress and comedian
1952 – Bob McClure, American baseball player and coach
1952 – Dave Valentin, American flautist (d. 2017)
1953 – Bill Drummond, British musician
1954 – Mo Brooks, American attorney and politician
1954 – Jerry Seinfeld, American comedian, actor and producer
1955 – Leslie Jordan, American actor, comedian, writer and singer (d. 2022)
1955 – Kate Mulgrew, American actress
1957 – Daniel Day-Lewis, British actor
1957 – Fiamē Naomi Mataʻafa, Samoan politician, 7th Prime Minister of Samoa
1957 – Joseph Morelle, American politician
1958 – Kevin Moore, English footballer (d. 2013)
1958 – Michelle Pfeiffer, American actress
1958 – Eve Plumb, American actress
1960 – Robert J. Sawyer, Canadian author and academic
1962 – Polly Samson, English novelist, lyricist and journalist
1963 – Mike Babcock, Canadian ice hockey player and coach
1964 – Federico Castelluccio, Italian-American actor, director, producer and screenwriter
1964 – Lúðvík Bergvinsson, Icelandic politician
1965 – Michel Bussi, French geographer, author, and academic
1965 – Amy Krouse Rosenthal, American author (d. 2017)
1966 – Christian Tetzlaff, German violinist
1968 – Kolinda Grabar-Kitarović, Croatian politician and diplomat, 4th President of Croatia
1969 – Paul Adelstein, American actor and writer
1970 – Andre Agassi, American tennis player
1970 – Uma Thurman, American actress
1975 – Garrison Starr, American singer-songwriter and producer
1975 – April Telek, Canadian actress
1976 – Micol Ostow, American author, editor and educator
1976 – God Shammgod, American basketball player and coach
1977 – Zuzana Hejdová, Czech tennis player
1977 – Claus Jensen, Danish international footballer and manager
1977 – David Sullivan, American film and television actor
1978 – Bob Bryan, American tennis player
1978 – Mike Bryan, American tennis player
1978 – Javier Colon, American singer-songwriter and musician
1978 – Tyler Labine, Canadian actor and comedian
1979 – Lee Dong-gook, South Korean footballer
1979 – Jo O'Meara, English pop singer
1980 – Mathieu Biron, Canadian ice hockey player
1980 – Bre Blair, Canadian actress
1981 – George McCartney, Northern Irish footballer
1983 – Megan Boone, American actress
1983 – Jay Cutler, American football player
1983 – Sam Jones III, American actor
1984 – Kirby Cote, Canadian swimmer
1984 – Lina Krasnoroutskaya, Russian tennis player
1986 – Byun Yo-han, South Korean actor
1986 – Lee Chae-young, South Korean actress
1987 – Rob Atkinson, English footballer
1987 – Sara Errani, Italian tennis player
1987 – Andre Russell, Jamaican cricketer
1988 – Alfred Hui, Hong Kong singer
1988 – Taoufik Makhloufi, Algerian athlete
1988 – Jonathan Toews, Canadian ice hockey player
1988 – Younha, South Korean singer-songwriter and record producer
1989 – Candace Owens, American political commentator and activist
1989 – Domagoj Vida, Croatian footballer
1990 – James Faulkner, Australian cricketer
1990 – Chris Johnson, American basketball player
1991 – Adam Smith, English footballer
1991 – Jung Hye-sung, South Korean actress
1991 – Misaki Doi, Japanese tennis player
1992 – Alina Rosenberg, German paralympic equestrian
1994 – Christina Shakovets, German tennis player
1996 – Katherine Langford, Australian actress
1997 – Lucas Tousart, French footballer
1998 – Kimberly Birrell, Australian tennis player
1998 – Mallory Pugh, American soccer player
1999 – Mateo Retegui, Argentine-Italian footballer
2001 – Danilo, Brazilian footballer
2002 – Sinja Kraus, Austrian tennis player
2005 – Aarón Anselmino, Argentine footballer
2006 – Xochitl Gomez, American actress
2007 – Infanta Sofía of Spain, Spanish princess |
April 29 | Deaths | Deaths |
April 29 | Pre-1600 | Pre-1600
1109 – Hugh of Cluny, French abbot (b. 1024)
1380 – Catherine of Siena, Italian mystic, philosopher and saint (b. 1347)
1594 – Thomas Cooper, English bishop, lexicographer, and theologian (b. 1517) |
April 29 | 1601–1900 | 1601–1900
1630 – Agrippa d'Aubigné, French soldier and poet (b. 1552)
1658 – John Cleveland, English poet and author (b. 1613)
1676 – Michiel de Ruyter, Dutch admiral (b. 1607)
1707 – George Farquhar, Irish-English actor and playwright (b. 1678)
1768 – Georg Brandt, Swedish chemist and mineralogist (b. 1694)
1776 – Edward Wortley Montagu, English explorer and author (b. 1713)
1833 – William Babington, Anglo-Irish physician and mineralogist (b. 1756)
1848 – Chester Ashley, American politician (b. 1790)
1854 – Henry Paget, 1st Marquess of Anglesey, English field marshal and politician, Lord Lieutenant of Ireland (b. 1768) |
April 29 | 1901–present | 1901–present
1903 – Godfrey Carter, Australian businessman and politician, 39th Mayor of Melbourne (b. 1830)
1903 – Paul Du Chaillu, French-American anthropologist and zoologist (b. 1835)
1905 – Ignacio Cervantes, Cuban pianist and composer (b. 1847)
1916 – Jørgen Pedersen Gram, Danish mathematician and academic (b. 1850)
1917 – Florence Farr, British actress, composer and director (b. 1860)
1922 – Richard Croker, Irish American political boss (b. 1843)
1924 – Ernest Fox Nichols, American educator and physicist (b. 1869)
1925 – Ralph Delahaye Paine, American journalist and author (b. 1871)
1933 – Clay Stone Briggs, American politician (b. 1876)
1933 – Constantine P. Cavafy, Greek poet and journalist (b. 1863)
1935 – Leroy Carr, American singer, songwriter and pianist (b. 1905)
1937 – William Gillette, American actor and playwright (b. 1853)
1943 – Joseph Achron, Russian composer and violinist (b. 1886)
1943 – Ricardo Viñes, Spanish pianist (b. 1875)
1944 – Billy Bitzer, American cinematographer (b. 1872)
1944 – Pyotr Stolyarsky, Soviet violinist (b. 1871)
1947 – Irving Fisher, American economist and statistician (b. 1867)
1951 – Ludwig Wittgenstein, Austrian-English philosopher and academic (b. 1889)
1956 – Wilhelm Ritter von Leeb, German field marshal (b. 1876)
1959 – Kenneth Anderson, English soldier and Governor of Gibraltar (b. 1891)
1966 – William Eccles, English physicist and engineer (b. 1875)
1966 – Paula Strasberg, American actress and acting coach (b. 1909)
1967 – J. B. Lenoir, American singer-songwriter and guitarist (b. 1929)
1968 – Aasa Helgesen, Norwegian midwife (b. 1877)
1968 – Lin Zhao, Chinese dissident (b. 1932)
1978 – Theo Helfrich, German race car driver (b. 1913)
1979 – Muhsin Ertuğrul, Turkish actor and director (b. 1892)
1979 – Hardie Gramatky, American author and illustrator (b. 1907)
1980 – Alfred Hitchcock, English-American director and producer (b. 1899)
1982 – Raymond Bussières, French actor, producer and screenwriter (b. 1907)
1992 – Mae Clarke, American actress (b. 1910)
1993 – Michael Gordon, American actor and director (b. 1909)
1993 – Mick Ronson, English guitarist, songwriter and producer (b. 1946)
1997 – Mike Royko, American journalist and author (b. 1932)
2000 – Phạm Văn Đồng, Vietnamese lieutenant and politician, 2nd Prime Minister of Vietnam (b. 1906)
2001 – Arthur B. C. Walker Jr., American physicist and academic (b. 1936)
2002 – Bob Akin, American race car driver and journalist (b. 1936)
2003 – Janko Bobetko, Croatian Army general and Chief of the General Staff (b. 1919)
2004 – John Henniker-Major, British diplomat and civil servant (b. 1916)
2005 – William J. Bell, American screenwriter and producer (b. 1927)
2005 – Louis Leithold, American mathematician and academic (b. 1924)
2006 – John Kenneth Galbraith, Canadian-American economist and diplomat, United States Ambassador to India (b. 1908)
2007 – Josh Hancock, American baseball player (b. 1978)
2007 – Dick Motz, New Zealand cricketer and rugby player (b. 1940)
2007 – Ivica Račan, Croatian politician, 7th Prime Minister of Croatia (b. 1944)
2008 – Gordon Bradley, English-American footballer (b. 1933)
2008 – Albert Hofmann, Swiss chemist and academic (b. 1906)
2010 – Avigdor Arikha, French-Israeli artist, printmaker and art historian (b. 1929)
2011 – Siamak Pourzand, Iranian journalist and critic (b. 1931)
2011 – Joanna Russ, American writer, academic and radical feminist (b. 1937)
2012 – Shukri Ghanem, Libyan politician, 22nd Prime Minister of Libya (b. 1942)
2012 – Joel Goldsmith, American composer and conductor (b. 1957)
2012 – Roland Moreno. French engineer, invented the smart card (b. 1945)
2012 – Kenny Roberts, American singer-songwriter (b. 1926)
2013 – Alex Elisala, New Zealand-Australian rugby player (b. 1992)
2013 – Pesah Grupper, Israeli politician, 13th Israel Minister of Agriculture (b. 1924)
2013 – John La Montaine, American pianist and composer (b. 1920)
2013 – Kevin Moore, English footballer (b. 1958)
2013 – Marianna Zachariadi, Greek pole vaulter (b. 1990)
2014 – Iveta Bartošová, Czech singer and actress (b. 1966)
2014 – Al Feldstein, American author and illustrator (b. 1925)
2014 – Bob Hoskins, English actor (b. 1942)
2015 – François Michelin, French businessman (b. 1926)
2015 – Jean Nidetch, American businesswoman, co-founded Weight Watchers (b. 1923)
2015 – Calvin Peete, American golfer (b. 1943)
2015 – Dan Walker, American lawyer and politician, 36th Governor of Illinois (b. 1922)
2016 – Dmytro Hnatyuk, Ukrainian singer (b. 1925)
2016 – Renato Corona, Filipino lawyer and jurist, 23rd Chief Justice of the Supreme Court of the Philippines (b. 1948)
2017 – R. Vidyasagar Rao, Indian bureaucrat and activist (b. 1939)
2018 – Luis García Meza, Bolivian general, 57th President of Bolivia (b. 1929)
2018 – Michael Martin, British politician (b. 1945)
2019 – Josef Šural, Czech footballer (b. 1990)
2020 – Irrfan Khan, Indian actor (b. 1967)
2020 – Guido Münch, Mexican astronomer and astrophysicist (b. 1921)
2021 – Cate Haste, English author (b. 1945)
2022 – Joanna Barnes, American actress and writer (b. 1934)
2023 – Padma Desai, Indian-American development economist (b. 1931) |
April 29 | Holidays and observances | Holidays and observances
Christian feast day:
Catherine of Siena (Catholic, Lutheran and Anglican Church)
Hugh of Cluny
Robert of Molesme
Wilfrid II
April 29 (Eastern Orthodox liturgics)
Day of Remembrance for all Victims of Chemical Warfare (United Nations)
International Dance Day (UNESCO)
Shōwa Day, traditionally the start of the Golden Week holiday period, which is April 29 and May 3–5. (Japan) |
April 29 | References | References |
April 29 | External links | External links
BBC: On This Day
Historical Events on April 29
Category:Days of April |
April 29 | Table of Content | pp-move, Events, Pre-1600, 1601–1900, 1901–present, Births, Pre-1600, 1601–1900, 1901–present, Deaths, Pre-1600, 1601–1900, 1901–present, Holidays and observances, References, External links |
August 14 | For | |
August 14 | Events | Events |
August 14 | Pre-1600 | Pre-1600
74 BC – A group of officials, led by the Western Han minister Huo Guang, present articles of impeachment against the new emperor, Liu He, to the imperial regent, Empress Dowager Shangguan.
29 BC – Octavian holds the second of three consecutive triumphs in Rome to celebrate the victory over the Dalmatian tribes.
1040 – King Duncan I is killed in battle against his first cousin and rival Macbeth. The latter succeeds him as King of Scotland.
1183 – Taira no Munemori and the Taira clan take the young Emperor Antoku and the three sacred treasures and flee to western Japan to escape pursuit by the Minamoto clan.
1264 – After tricking the Venetian galley fleet into sailing east to the Levant, the Genoese capture an entire Venetian trade convoy at the Battle of Saseno.
1352 – War of the Breton Succession: Anglo-Bretons defeat the French in the Battle of Mauron.
1370 – Charles IV, Holy Roman Emperor, grants city privileges to Karlovy Vary.
1385 – Portuguese Crisis of 1383–85: Battle of Aljubarrota: Portuguese forces commanded by John I of Portugal defeat the Castilian army of John I of Castile.
1592 – The first sighting of the Falkland Islands by John Davis.
1598 – Nine Years' War: Battle of the Yellow Ford: Irish forces under Hugh O'Neill, Earl of Tyrone, defeat an English expeditionary force under Henry Bagenal. |
August 14 | 1601–1900 | 1601–1900
1720 – The Spanish military Villasur expedition is defeated by Pawnee and Otoe warriors near present-day Columbus, Nebraska.
1784 – Russian colonization of North America: Awa'uq Massacre: The Russian fur trader Grigory Shelikhov storms a Kodiak Island Alutiit refuge rock on Sitkalidak Island, killing 500+ Alutiit.Richard A. Knecht, Sven Haakanson, and Shawn Dickson (2002). "Awa'uq: discovery and excavation of an 18th century Alutiiq refuge rock in the Kodiak Archipelago". In To the Aleutians and Beyond:, Bruno Frohlich, Albert S. Harper, and Rolf Gilberg, editors, pp. 177–191. Publications of the National Museum Ethnographical Series, Vol. 20. Department of Ethnography, National Museum of Denmark, Copenhagen. the Anthropology of William S. Laughlin.
1790 – The Treaty of Wereloe ended the 1788–1790 Russo-Swedish War.
1791 – Slaves from plantations in Saint-Domingue hold a Vodou ceremony led by houngan Dutty Boukman at Bois Caïman, marking the start of the Haitian Revolution.
1814 – A cease fire agreement, called the Convention of Moss, ended the Swedish–Norwegian War.
1816 – The United Kingdom formally annexes the Tristan da Cunha archipelago, administering the islands from the Cape Colony in South Africa.
1842 – American Indian Wars: Second Seminole War ends, with the Seminoles forced from Florida.
1848 – Oregon Territory is organized by act of Congress.
1880 – Construction of Cologne Cathedral, the most famous landmark in Cologne, Germany, is completed.
1885 – Japan's first patent is issued to the inventor of a rust-proof paint.
1893 – France becomes the first country to introduce motor vehicle registration.
1900 – Battle of Peking: The Eight-Nation Alliance occupies Beijing, China, in a campaign to end the bloody Boxer Rebellion in China. |
August 14 | 1901–present | 1901–present
1901 – The first claimed powered flight, by Gustave Whitehead in his Number 21.
1914 – World War I: Start of the Battle of Lorraine, an unsuccessful French offensive.
1917 – World War I: The Republic of China, which had heretofore been shipping labourers to Europe to assist in the war effort, officially declares war on the Central Powers, although it will continue to send to Europe labourers instead of combatants for the remaining duration of the war.
1920 – The 1920 Summer Olympics, having started four months earlier, officially open in Antwerp, Belgium, with the newly adopted Olympic flag and the Olympic oath being raised and taken at the Opening Ceremony for the first time in Olympic history.
1921 – Tannu Uriankhai, later Tuvan People's Republic is established as a completely independent country (which is supported by Soviet Russia).
1933 – Loggers cause a forest fire in the Coast Range of Oregon, later known as the first forest fire of the Tillamook Burn; destroying of land.
1935 – Franklin D. Roosevelt signs the Social Security Act, creating a government pension system for the retired.
1936 – Rainey Bethea is hanged in Owensboro, Kentucky in the last known public execution in the United States.
1941 – World War II: Winston Churchill and Franklin D. Roosevelt sign the Atlantic Charter of war stating postwar aims.
1947 – Pakistan gains independence from the British Empire as the Dominion of Pakistan, due to the partition of India.
1948 – An Idaho Department of Fish and Game program to relocate beavers known as Beaver drop occurred. This program relocated beavers from Northwestern Idaho to Central Idaho by airplane and then parachuting the beavers into the Chamberlain Basin .
1959 – Founding and first official meeting of the American Football League.
1967 – UK Marine Broadcasting Offences Act 1967 declares participation in offshore pirate radio illegal.
1969 – The Troubles: British troops are deployed in Northern Ireland as political and sectarian violence breaks out, marking the start of the 37-year Operation Banner.
1971 – Bahrain declares independence from Britain.
1972 – An Ilyushin Il-62 airliner crashes near Königs Wusterhausen, East Germany killing 156 people.
1980 – Lech Wałęsa leads strikes at the Gdańsk, Poland shipyards.
1994 – Ilich Ramírez Sánchez, also known as "Carlos the Jackal", is captured.
1996 – Greek Cypriot refugee Solomos Solomou is shot and killed by a Turkish security officer while trying to climb a flagpole in order to remove a Turkish flag from its mast in the United Nations Buffer Zone in Cyprus.
2003 – A widescale power blackout affects the northeast United States and Canada.
2005 – Helios Airways Flight 522, en route from Larnaca, Cyprus to Prague, Czech Republic via Athens, crashes in the hills near Grammatiko, Greece, killing 121 passengers and crew.
2006 – Lebanon War: A ceasefire takes effect three days after the United Nations Security Council's approval of United Nations Security Council Resolution 1701, formally ending hostilities between Lebanon and Israel.
2006 – Sri Lankan Civil War: Sixty-one schoolgirls killed in Chencholai bombing by Sri Lankan Air Force air strike.
2007 – The Kahtaniya bombings kill at least 500 people.
2013 – Egypt declares a state of emergency as security forces kill hundreds of demonstrators supporting former president Mohamed Morsi.
2013 – UPS Airlines Flight 1354 crashes short of the runway at Birmingham–Shuttlesworth International Airport, killing both crew members on board.
2015 – The U.S. Embassy in Havana, Cuba re-opens after 54 years of being closed when Cuba–United States relations were broken off.
2018 – The collapse of the Ponte Morandi bridge in Genoa, Italy, left 16 people injured and 43 people killed.
2021 – A magnitude 7.2 earthquake strikes southwestern Haiti, killing at least 2,248 people and causing a humanitarian crisis.
2022 – An explosion destroys a market in Armenia, killing six people and injuring dozens.
2023 – Former U.S. President Donald Trump is charged in Georgia along with 18 others in attempting to overturn the results of the 2020 election in that state, his fourth indictment of 2023. |
August 14 | Births | Births |
August 14 | Pre-1600 | Pre-1600
1479 – Catherine of York (d. 1527)
1499 – John de Vere, 14th Earl of Oxford, English politician (d. 1526)
1502 – Pieter Coecke van Aelst, Flemish painter (d. 1550)
1530 – Giambattista Benedetti, Italian mathematician and physicist (d. 1590)
1552 – Paolo Sarpi, Italian writer (d. 1623)
1599 – Méric Casaubon, Swiss-English scholar and author (d. 1671) |
August 14 | 1601–1900 | 1601–1900
1642 – Cosimo III de' Medici, Grand Duke of Tuscany (d. 1723)
1653 – Christopher Monck, 2nd Duke of Albemarle, English colonel and politician, Lieutenant Governor of Jamaica (d. 1688)
1688 – Frederick William I of Prussia (d. 1740)
1714 – Claude Joseph Vernet, French painter (d. 1789)
1738 – Leopold Hofmann, Austrian composer and conductor (d. 1793)
1742 – Pope Pius VII (d. 1823)
1758 – Carle Vernet, French painter and lithographer (d. 1836)
1777 – Hans Christian Ørsted, Danish physicist and chemist (d. 1851)
1802 – Letitia Elizabeth Landon, English poet and novelist (d. 1838)
1814 – Charlotte Fowler Wells, American phrenologist and publisher (d. 1901)
1817 – Alexander H. Bailey, American lawyer, judge, and politician (d. 1874)
1840 – Richard von Krafft-Ebing, German-Austrian psychologist and author (d. 1902)
1847 – Robert Comtesse, Swiss lawyer and politician (d. 1922)
1848 – Margaret Lindsay Huggins, Anglo-Irish astronomer and author (d. 1915)
1851 – Doc Holliday, American dentist and gambler (d. 1887)
1860 – Ernest Thompson Seton, American author, artist, and naturalist (d. 1946)
1863 – Ernest Thayer, American poet and author (d. 1940)
1865 – Guido Castelnuovo, Italian mathematician and academic (d. 1952)
1866 – Charles Jean de la Vallée-Poussin, Belgian mathematician and academic (d. 1962)
1867 – Cupid Childs, American baseball player (d. 1912)
1867 – John Galsworthy, English novelist and playwright, Nobel Prize laureate (d. 1933)
1871 – Guangxu Emperor of China (d. 1908)
1875 – Mstislav Dobuzhinsky, Russian-Lithuanian painter and illustrator (d. 1957)
1876 – Alexander I of Serbia (d. 1903)
1881 – Francis Ford, American actor, director, producer, and screenwriter (d. 1953)
1883 – Ernest Everett Just, American biologist and academic (d. 1941)
1886 – Arthur Jeffrey Dempster, Canadian-American physicist and academic (d. 1950)
1889 – Otto Tief, Estonian lawyer and politician, Prime Minister of Estonia (d. 1976)
1890 – Bruno Tesch, German chemist and businessman (d. 1946)
1892 – Kaikhosru Shapurji Sorabji, English pianist, composer, and critic (d. 1988)
1894 – Frank Burge, Australian rugby league player and coach (d. 1958)
1895 – Jack Gregory, Australian cricketer (d. 1973)
1895 – Amaza Lee Meredith, American architect (d. 1984)
1896 – Albert Ball, English fighter pilot (d. 1917)
1896 – Theodor Luts, Estonian director and cinematographer (d. 1980)
1900 – Margret Boveri, German journalist (d. 1975) |
August 14 | 1901–present | 1901–present
1910 – Nüzhet Gökdoğan, Turkish astronomer and mathematician (d. 2003)
1910 – Willy Ronis, French photographer (d. 2009)
1910 – Pierre Schaeffer, French composer and producer (d. 1995)
1912 – Frank Oppenheimer, American physicist and academic (d. 1985)
1913 – Hector Crawford, Australian director and producer (d. 1991)
1913 – Paul Dean, American baseball player (d. 1981)
1914 – Herman Branson, American physicist, chemist, and academic (d. 1995)
1915 – B. A. Santamaria, Australian political activist and publisher (d. 1998)
1916 – Frank and John Craighead, American naturalists (twins, Frank d. 2001, John d. 2016)
1916 – Wellington Mara, American businessman (d. 2005)
1923 – Alice Ghostley, American actress (d. 2007)
1924 – Sverre Fehn, Norwegian architect, designed the Hedmark Museum (d. 2009)
1924 – Georges Prêtre, French conductor (d. 2017)
1925 – Russell Baker, American critic and essayist (d. 2019)
1926 – René Goscinny, French author and illustrator (d. 1977)
1926 – Buddy Greco, American singer and pianist (d. 2017)
1928 – Lina Wertmüller, Italian director and screenwriter (d. 2021)
1929 – Giacomo Capuzzi, Italian Roman Catholic prelate, bishop of the Roman Catholic Diocese of Lodi from 1989 to 2005 (d. 2021).
1929 – Dick Tiger, Nigerian boxer (d. 1971)
1930 – Arthur Latham, British politician and Member of Parliament (d. 2016)
1930 – Earl Weaver, American baseball player and manager (d. 2013)
1931 – Frederic Raphael, American journalist, author, and screenwriter
1932 – Lee Hoffman, American author (d. 2007)
1933 – Richard R. Ernst, Swiss chemist and academic, Nobel Prize laureate (d. 2021)
1935 – John Brodie, American football player
1938 – Bennie Muller, Dutch footballer (d. 2024)
1941 – David Crosby, American singer-songwriter and guitarist (d. 2023)
1941 – Connie Smith, American country music singer-songwriter and guitarist
1942 – Willie Dunn, Canadian singer-songwriter and producer (d. 2013)
1943 – Ronnie Campbell, English miner and politician (d. 2024)
1943 – Ben Sidran, American jazz and rock keyboardist
1945 – Steve Martin, American actor, comedian, musician, producer, and screenwriter
1945 – Wim Wenders, German director, producer, and screenwriter
1946 – Antonio Fargas, American actor
1946 – Larry Graham, American soul/funk bass player and singer-songwriter
1946 – Susan Saint James, American actress
1946 – Tom Walkinshaw, Scottish race car driver and businessman (d. 2010)
1947 – Maddy Prior, English folk singer
1947 – Danielle Steel, American author
1947 – Joop van Daele, Dutch footballer
1949 – Bob Backlund, American wrestler
1949 – Morten Olsen, Danish footballer
1950 – Gary Larson, American cartoonist
1951 – Slim Dunlap, American singer-songwriter and guitarist (d. 2024)
1951 – Carl Lumbly, American actor
1952 – Debbie Meyer, American swimmer
1953 – James Horner, American composer and conductor (d. 2015)
1954 – Mark Fidrych, American baseball player and sportscaster (d. 2009)
1954 – Stanley A. McChrystal, American general
1956 – Jackée Harry, American actress and television personality
1956 – Andy King, English footballer and manager (d. 2015)
1956 – Rusty Wallace, American race car driver
1957 – Peter Costello, Australian lawyer and politician
1959 – Frank Brickowski, American basketball player
1959 – Marcia Gay Harden, American actress
1959 – Magic Johnson, American basketball player and coach
1960 – Sarah Brightman, English singer and actress
1960 – Fred Roberts, American basketball player
1961 – Susan Olsen, American actress and radio host
1962 – Mark Gubicza, American baseball player
1963 – José Cóceres, Argentinian golfer
1964 – Neal Anderson, American football player and coach
1964 – Jason Dunstall, Australian footballer
1965 – Paul Broadhurst, English golfer
1966 – Halle Berry, American model, actress, and producer
1966 – Karl Petter Løken, Swedish-Norwegian footballer
1968 – Ben Bass, American actor
1968 – Catherine Bell, English-American actress and producer
1968 – Darren Clarke, Northern Irish golfer
1968 – Jason Leonard, English rugby player
1969 – Tracy Caldwell Dyson, American chemist and astronaut
1969 – Stig Tøfting, Danish footballer
1970 – Kevin Cadogan, American rock guitarist
1971 – Raoul Bova, Italian actor, producer, and screenwriter
1971 – Benito Carbone, Italian footballer
1971 – Peter Franzén, Finnish actor
1971 – Mark Loretta, American baseball player
1972 – Laurent Lamothe, Haitian businessman and politician, Prime Minister of Haiti
1973 – Jared Borgetti, Mexican footballer
1973 – Kieren Perkins, Australian swimmer
1974 – Chucky Atkins, American basketball player
1974 – Christopher Gorham, American actor
1975 – Mike Vrabel, American football player
1976 – Fabrizio Donato, Italian triple jumper
1977 – Juan Pierre, American baseball player
1978 – Anastasios Kyriakos, Greek footballer
1978 – Greg Rawlinson, New Zealand rugby player
1979 – Paul Burgess, Australian pole vaulter
1980 – Peter Malinauskas, Australian politician, 47th Premier of South Australia
1981 – Earl Barron, American basketball player
1981 – Paul Gallen, Australian rugby league player, boxer, and sportscaster
1981 – Julius Jones, American football player
1981 – Kofi Kingston, Ghanaian-American wrestler
1981 – Scott Lipsky, American tennis player
1983 – Elena Baltacha, Ukrainian-Scottish tennis player (d. 2014)
1983 – Mila Kunis, Ukrainian-American actress
1983 – Lamorne Morris, American actor and comedian
1983 – Spencer Pratt, American television personality
1984 – Eva Birnerová, Czech tennis player
1984 – Clay Buchholz, American baseball player
1984 – Giorgio Chiellini, Italian footballer
1984 – Josh Gorges, Canadian ice hockey player
1984 – Nick Grimshaw, English radio and television host
1984 – Nicola Slater, Scottish tennis player
1984 – Robin Söderling, Swedish tennis player
1985 – Christian Gentner, German footballer
1985 – Shea Weber, Canadian ice hockey player
1986 – Braian Rodríguez, Uruguayan footballer
1987 – Johnny Gargano, American wrestler
1987 – David Peralta, Venezuelan baseball player
1987 – Tim Tebow, American football and baseball player and sportscaster
1989 – Ander Herrera, Spanish footballer
1989 – Kyle Turris, Canadian ice hockey player
1991 – Richard Freitag, German ski jumper
1991 – Giovanny Gallegos, Mexican baseball player
1994 – Maya Jama, British TV presenter.
1995 – Léolia Jeanjean, French tennis player
1997 – Greet Minnen, Belgian tennis player
1998 – Doechii, American rapper
2000 – Johan Rojas, Dominican baseball player
2004 – Marsai Martin, American actress and producer |
August 14 | Deaths | Deaths |
August 14 | Pre-1600 | Pre-1600
582 – Tiberius II Constantine, Byzantine emperor
1040 – Duncan I of Scotland
1167 – Rainald of Dassel, Italian archbishop
1204 – Minamoto no Yoriie, second Shōgun of the Kamakura shogunate: 7月18日 ［愚管抄］ 修善寺にて、また頼家入道をば指ころしてけり。とみにえとりつめざりければ、頸に 緒をつけ、ふぐりを取などしてころしてけりと聞えき。人はいみじくたけきも力及ば ぬことなりけり。ひきは其郡に父の党とて、みせやの大夫行時と云う者のむすめを妻 にして、一万御前が母をばもうけたるなり。その行時は又兒玉党にしたるなり。
1433 – John I of Portugal (b. 1357)
1464 – Pope Pius II (b. 1405)
1573 – Saitō Tatsuoki, Japanese daimyō (b. 1548) |
August 14 | 1601–1900 | 1601–1900
1691 – Richard Talbot, 1st Earl of Tyrconnell, Irish soldier and politician (b. 1630)
1716 – Madre María Rosa, Capuchin nun from Spain, to Peru (b. 1660)
1727 – William Croft, English organist and composer (b. 1678)
1774 – Johann Jakob Reiske, German physician and scholar (b. 1716)
1784 – Nathaniel Hone the Elder, Irish-born English painter and academic (b. 1718)
1852 – Margaret Taylor, First Lady of the United States (b. 1788)
1854 – Carl Carl, Polish-born actor and theatre director (b. 1787)
1860 – André Marie Constant Duméril, French zoologist and entomologist (b. 1774)
1870 – David Farragut, American admiral (b. 1801)
1890 – Michael J. McGivney, American priest, founded the Knights of Columbus (b. 1852)
1891 – Sarah Childress Polk, First Lady of the United States (b. 1803) |
August 14 | 1901–present | 1901–present
1905 – Simeon Solomon, English soldier and painter (b. 1840)
1909 – William Stanley, British engineer and author (b. 1829)
1922 – Rebecca Cole, American physician and social reformer (b. 1846)
1928 – Klabund, German author and poet (b. 1890)
1938 – Hugh Trumble, Australian cricketer and accountant (b. 1876)
1941 – Maximilian Kolbe, Polish martyr and saint (b. 1894)
1941 – Paul Sabatier, French chemist and academic, Nobel Prize laureate (b. 1854)
1943 – Joe Kelley, American baseball player and manager (b. 1871)
1948 – Eliška Misáková, Czech gymnast (b. 1926)
1951 – William Randolph Hearst, American publisher and politician, founded the Hearst Corporation (b. 1863)
1954 – Hugo Eckener, German pilot and designer (b. 1868)
1955 – Herbert Putnam, American lawyer and publisher, Librarian of Congress (b. 1861)
1956 – Bertolt Brecht, German poet, playwright, and director (b. 1898)
1956 – Konstantin von Neurath, German lawyer and politician, Reich Minister of Foreign Affairs (b. 1873)
1958 – Frédéric Joliot-Curie, French physicist and chemist, Nobel Prize laureate (b. 1900)
1963 – Clifford Odets, American director, playwright, and screenwriter (b. 1906)
1964 – Johnny Burnette, American singer-songwriter (b. 1934)
1965 – Vello Kaaristo, Estonian skier (b. 1911)
1967 – Bob Anderson, English motorcycle racer and race car driver (b. 1931)
1972 – Oscar Levant, American actor, pianist, and composer (b. 1906)
1972 – Jules Romains, French author and poet (b. 1885)
1973 – Fred Gipson, American journalist and author (b. 1908)
1978 – Nicolas Bentley, English author and illustrator (b. 1907)
1980 – Dorothy Stratten, Canadian-American model and actress (b. 1960)
1981 – Karl Böhm, Austrian conductor and director (b. 1894)
1981 – Dudley Nourse, South African cricketer (b. 1910)
1982 – Mahasi Sayadaw, Burmese monk and philosopher (b. 1904)
1984 – Spud Davis, American baseball player, coach, and manager (b. 1904)
1984 – J. B. Priestley, English novelist and playwright (b. 1894)
1985 – Gale Sondergaard, American actress (b. 1899)
1988 – Roy Buchanan, American singer-songwriter and guitarist (b. 1939)
1988 – Robert Calvert, South African-English singer-songwriter and playwright (b. 1945)
1988 – Enzo Ferrari, Italian race car driver and businessman, founded Ferrari (b. 1898)
1991 – Alberto Crespo, Argentinian race car driver (b. 1920)
1992 – John Sirica, American lawyer and judge (b. 1904)
1994 – Elias Canetti, Bulgarian-Swiss author, Nobel Prize laureate (b. 1905)
1994 – Alice Childress, American actress, playwright, and author (b. 1912)
1996 – Sergiu Celibidache, Romanian conductor and composer (b. 1912)
1999 – Pee Wee Reese, American baseball player and sportscaster (b. 1918)
2002 – Larry Rivers, American painter and sculptor (b. 1923)
2003 – Helmut Rahn, German footballer (b. 1929)
2004 – Czesław Miłosz, Polish-born American novelist, essayist, and poet, Nobel Prize laureate (b. 1911)
2004 – Trevor Skeet, New Zealand-English lawyer and politician (b. 1918)
2006 – Bruno Kirby, American actor (b. 1949)
2007 – Tikhon Khrennikov, Russian pianist and composer (b. 1913)
2010 – Herman Leonard, American photographer (b. 1923)
2012 – Vilasrao Deshmukh, Indian lawyer and politician, Chief Minister of Maharashtra (b. 1945)
2012 – Svetozar Gligorić, Serbian chess player (b. 1923)
2012 – Phyllis Thaxter, American actress (b. 1919)
2013 – Jack Germond, American journalist and author (b. 1928)
2014 – Leonard Fein, American journalist and academic, co-founded Moment Magazine (b. 1934)
2014 – George V. Hansen, American politician (b. 1930)
2015 – Bob Johnston, American songwriter and producer (b. 1932)
2016 – Fyvush Finkel, American actor (b. 1922)
2018 – Jill Janus, American singer (b. 1975)
2019 – Polly Farmer, Australian footballer and coach (b. 1935)
2020 – Julian Bream, English classical guitarist and lutenist (b. 1933)
2020 – Angela Buxton, British tennis player (b. 1934)
2020 – James R. Thompson, American politician, Governor of Illinois (b. 1936)
2021 – Michael Aung-Thwin, American historian and scholar of Burmese and Southeast Asian history (b. 1946)
2023 – Delwar Hossain Sayeedi, Bangladeshi Islamic lecturer, politician (b. 1940)
2024 – Gena Rowlands, American actress (b. 1930) |
August 14 | Holidays and observances | Holidays and observances
Christian feast day:
Arnold of Soissons
Domingo Ibáñez de Erquicia
Eusebius of Rome
Jonathan Myrick Daniels (Episcopal Church)
Maximilian Kolbe
National Navajo Code Talkers Day is a holiday in the United States honoring Navajo code talkers in the military.
Falklands Day is the celebration of the first sighting of the Falkland Islands by John Davis in 1592.
Independence Day celebrates the independence of Pakistan from the United Kingdom in 1947.
Partition Horrors Remembrance Day commemorates the victims and sufferings of people during the Partition of India in 1947. |
August 14 | References | References |
August 14 | External links | External links
Category:Days of August |
August 14 | Table of Content | For, Events, Pre-1600, 1601–1900, 1901–present, Births, Pre-1600, 1601–1900, 1901–present, Deaths, Pre-1600, 1601–1900, 1901–present, Holidays and observances, References, External links |
Absolute zero | short description | thumb|upright=0.5|Zero kelvin (−273.15 °C) is defined as absolute zero.
Absolute zero is the coldest point on the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value. The fundamental particles of nature have minimum vibrational motion, retaining only quantum mechanical, zero-point energy-induced particle motion. The theoretical temperature is determined by extrapolating the ideal gas law; by international agreement, absolute zero is taken as 0 kelvin (International System of Units), which is −273.15 degrees on the Celsius scale, and equals −459.67 degrees on the Fahrenheit scale (United States customary units or imperial units). The Kelvin and Rankine temperature scales set their zero points at absolute zero by definition.
It is commonly thought of as the lowest temperature possible, but it is not the lowest enthalpy state possible, because all real substances begin to depart from the ideal gas when cooled as they approach the change of state to liquid, and then to solid; and the sum of the enthalpy of vaporization (gas to liquid) and enthalpy of fusion (liquid to solid) exceeds the ideal gas's change in enthalpy to absolute zero. In the quantum-mechanical description, matter at absolute zero is in its ground state, the point of lowest internal energy.
The laws of thermodynamics show that absolute zero cannot be reached using only thermodynamic means, because the temperature of the substance being cooled approaches the temperature of the cooling agent asymptotically.. Even a system at absolute zero, if it could somehow be achieved, would still possess quantum mechanical zero-point energy, the energy of its ground state at absolute zero; the kinetic energy of the ground state cannot be removed.
Scientists and technologists routinely achieve temperatures close to absolute zero, where matter exhibits quantum effects such as superconductivity, superfluidity, and Bose–Einstein condensation. |
Absolute zero | Thermodynamics near absolute zero | Thermodynamics near absolute zero
At temperatures near , nearly all molecular motion ceases and ΔS = 0 for any adiabatic process, where S is the entropy. In such a circumstance, pure substances can (ideally) form perfect crystals with no structural imperfections as T → 0. Max Planck's strong form of the third law of thermodynamics states the entropy of a perfect crystal vanishes at absolute zero. The original Nernst heat theorem makes the weaker and less controversial claim that the entropy change for any isothermal process approaches zero as T → 0:
The implication is that the entropy of a perfect crystal approaches a constant value. An adiabat is a state with constant entropy, typically represented on a graph as a curve in a manner similar to isotherms and isobars.
The Nernst postulate identifies the isotherm T = 0 as coincident with the adiabat S = 0, although other isotherms and adiabats are distinct. As no two adiabats intersect, no other adiabat can intersect the T = 0 isotherm. Consequently no adiabatic process initiated at nonzero temperature can lead to zero temperature (≈ Callen, pp. 189–190).
A perfect crystal is one in which the internal lattice structure extends uninterrupted in all directions. The perfect order can be represented by translational symmetry along three (not usually orthogonal) axes. Every lattice element of the structure is in its proper place, whether it is a single atom or a molecular grouping. For substances that exist in two (or more) stable crystalline forms, such as diamond and graphite for carbon, there is a kind of chemical degeneracy. The question remains whether both can have zero entropy at T = 0 even though each is perfectly ordered.
Perfect crystals never occur in practice; imperfections, and even entire amorphous material inclusions, can and do get "frozen in" at low temperatures, so transitions to more stable states do not occur.
Using the Debye model, the specific heat and entropy of a pure crystal are proportional to T 3, while the enthalpy and chemical potential are proportional to T 4 (Guggenheim, p. 111). These quantities drop toward their T = 0 limiting values and approach with zero slopes. For the specific heats at least, the limiting value itself is definitely zero, as borne out by experiments to below 10 K. Even the less detailed Einstein model shows this curious drop in specific heats. In fact, all specific heats vanish at absolute zero, not just those of crystals. Likewise for the coefficient of thermal expansion. Maxwell's relations show that various other quantities also vanish. These phenomena were unanticipated.
Since the relation between changes in Gibbs free energy (G), the enthalpy (H) and the entropy is
thus, as T decreases, ΔG and ΔH approach each other (so long as ΔS is bounded). Experimentally, it is found that all spontaneous processes (including chemical reactions) result in a decrease in G as they proceed toward equilibrium. If ΔS and/or T are small, the condition ΔG < 0 may imply that ΔH < 0, which would indicate an exothermic reaction. However, this is not required; endothermic reactions can proceed spontaneously if the TΔS term is large enough.
Moreover, the slopes of the derivatives of ΔG and ΔH converge and are equal to zero at T = 0. This ensures that ΔG and ΔH are nearly the same over a considerable range of temperatures and justifies the approximate empirical Principle of Thomsen and Berthelot, which states that the equilibrium state to which a system proceeds is the one that evolves the greatest amount of heat, i.e., an actual process is the most exothermic one (Callen, pp. 186–187).
One model that estimates the properties of an electron gas at absolute zero in metals is the Fermi gas. The electrons, being fermions, must be in different quantum states, which leads the electrons to get very high typical velocities, even at absolute zero. The maximum energy that electrons can have at absolute zero is called the Fermi energy. The Fermi temperature is defined as this maximum energy divided by the Boltzmann constant, and is on the order of 80,000 K for typical electron densities found in metals. For temperatures significantly below the Fermi temperature, the electrons behave in almost the same way as at absolute zero. This explains the failure of the classical equipartition theorem for metals that eluded classical physicists in the late 19th century. |
Absolute zero | Relation with Bose–Einstein condensate | Relation with Bose–Einstein condensate
left|thumb|Velocity-distribution data of a gas of rubidium atoms at a temperature within a few billionths of a degree above absolute zero. Left: just before the appearance of a Bose–Einstein condensate. Center: just after the appearance of the condensate. Right: after further evaporation, leaving a sample of nearly pure condensate.
A Bose–Einstein condensate (BEC) is a state of matter of a dilute gas of weakly interacting bosons confined in an external potential and cooled to temperatures very near absolute zero. Under such conditions, a large fraction of the bosons occupy the lowest quantum state of the external potential, at which point quantum effects become apparent on a macroscopic scale.
This state of matter was first predicted by Satyendra Nath Bose and Albert Einstein in 1924–1925. Bose first sent a paper to Einstein on the quantum statistics of light quanta (now called photons). Einstein was impressed, translated the paper from English to German and submitted it for Bose to the Zeitschrift für Physik, which published it. Einstein then extended Bose's ideas to material particles (or matter) in two other papers.Clark, Ronald W. "Einstein: The Life and Times" (Avon Books, 1971) pp. 408–9
Seventy years later, in 1995, the first gaseous condensate was produced by Eric Cornell and Carl Wieman at the University of Colorado at Boulder NIST-JILA lab, using a gas of rubidium atoms cooled to ().
In 2003, researchers at the Massachusetts Institute of Technology (MIT) achieved a temperature of () in a BEC of sodium atoms. The associated black body (peak emittance) wavelength of 6.4 megameters is roughly the radius of Earth.
In 2021, University of Bremen physicists achieved a BEC with a temperature of only , the current coldest temperature record. |
Absolute zero | Absolute temperature scales | Absolute temperature scales
Absolute, or thermodynamic, temperature is conventionally measured in kelvin (Celsius-scaled increments) and in the Rankine scale (Fahrenheit-scaled increments) with increasing rarity. Absolute temperature measurement is uniquely determined by a multiplicative constant which specifies the size of the degree, so the ratios of two absolute temperatures, T2/T1, are the same in all scales. The most transparent definition of this standard comes from the Maxwell–Boltzmann distribution. It can also be found in Fermi–Dirac statistics (for particles of half-integer spin) and Bose–Einstein statistics (for particles of integer spin). All of these define the relative numbers of particles in a system as decreasing exponential functions of energy (at the particle level) over kT, with k representing the Boltzmann constant and T representing the temperature observed at the macroscopic level. |
Absolute zero | Negative temperatures | Negative temperatures
Temperatures that are expressed as negative numbers on the familiar Celsius or Fahrenheit scales are simply colder than the zero points of those scales. Certain systems can achieve truly negative temperatures; that is, their thermodynamic temperature (expressed in kelvins) can be of a negative quantity. A system with a truly negative temperature is not colder than absolute zero. Rather, a system with a negative temperature is hotter than any system with a positive temperature, in the sense that if a negative-temperature system and a positive-temperature system come in contact, heat flows from the negative to the positive-temperature system.
Most familiar systems cannot achieve negative temperatures because adding energy always increases their entropy. However, some systems have a maximum amount of energy that they can hold, and as they approach that maximum energy their entropy actually begins to decrease. Because temperature is defined by the relationship between energy and entropy, such a system's temperature becomes negative, even though energy is being added. As a result, the Boltzmann factor for states of systems at negative temperature increases rather than decreases with increasing state energy. Therefore, no complete system, i.e. including the electromagnetic modes, can have negative temperatures, since there is no highest energy state, so that the sum of the probabilities of the states would diverge for negative temperatures. However, for quasi-equilibrium systems (e.g. spins out of equilibrium with the electromagnetic field) this argument does not apply, and negative effective temperatures are attainable.
On 3 January 2013, physicists announced that for the first time they had created a quantum gas made up of potassium atoms with a negative temperature in motional degrees of freedom. |
Absolute zero | History | History
thumb|upright=1.05|Robert Boyle pioneered the idea of an absolute zero.
One of the first to discuss the possibility of an absolute minimal temperature was Robert Boyle. His 1665 New Experiments and Observations touching Cold, articulated the dispute known as the primum frigidum. The concept was well known among naturalists of the time. Some contended an absolute minimum temperature occurred within earth (as one of the four classical elements), others within water, others air, and some more recently within nitre. But all of them seemed to agree that, "There is some body or other that is of its own nature supremely cold and by participation of which all other bodies obtain that quality." |
Absolute zero | Limit to the "degree of cold" | Limit to the "degree of cold"
The question of whether there is a limit to the degree of coldness possible, and, if so, where the zero must be placed, was first addressed by the French physicist Guillaume Amontons in 1703, in connection with his improvements in the air thermometer. His instrument indicated temperatures by the height at which a certain mass of air sustained a column of mercury—the pressure, or "spring" of the air varying with temperature. Amontons therefore argued that the zero of his thermometer would be that temperature at which the spring of the air was reduced to nothing. Amontons described the relation between his new thermometer (which was based on the expansion and contraction of alcohol (esprit de vin)) and the old thermometer (which was based on air). From p. 52: " […] d'où il paroît que l'extrême froid de ce Thermométre seroit celui qui réduiroit l'air à ne soutenir aucune charge par son ressort, […] " ([…] whence it appears that the extreme cold of this [air] thermometer would be that which would reduce the air to supporting no load by its spring, […]) In other words, the lowest temperature which can be measured by a thermometer which is based on the expansion and contraction of air is that temperature at which the air's pressure ("spring") has decreased to zero. He used a scale that marked the boiling point of water at +73 and the melting point of ice at +, so that the zero was equivalent to about −240 on the Celsius scale. Amontons held that the absolute zero cannot be reached, so never attempted to compute it explicitly. The value of −240 °C, or "431 divisions [in Fahrenheit's thermometer] below the cold of freezing water" was published by George Martine in 1740.
This close approximation to the modern value of −273.15 °C for the zero of the air thermometer was further improved upon in 1779 by Johann Heinrich Lambert, who observed that might be regarded as absolute cold.
Values of this order for the absolute zero were not, however, universally accepted about this period. Pierre-Simon Laplace and Antoine Lavoisier, in their 1780 treatise on heat, arrived at values ranging from 1,500 to 3,000 below the freezing point of water, and thought that in any case it must be at least 600 below. John Dalton in his Chemical Philosophy gave ten calculations of this value, and finally adopted −3,000 °C as the natural zero of temperature. |
Absolute zero | Charles's law | Charles's law
From 1787 to 1802, it was determined by Jacques Charles (unpublished), John Dalton,J. Dalton (1802), "Essay II. On the force of steam or vapour from water and various other liquids, both in vacuum and in air" and Essay IV. "On the expansion of elastic fluids by heat" , Memoirs of the Literary and Philosophical Society of Manchester, vol. 8, pt. 2, pp. 550–574, 595–602. and Joseph Louis Gay-Lussac. English translation (extract). that, at constant pressure, ideal gases expanded or contracted their volume linearly (Charles's law) by about 1/273 parts per degree Celsius of temperature's change up or down, between 0° and 100° C. This suggested that the volume of a gas cooled at about −273 °C would reach zero. |
Absolute zero | Lord Kelvin's work | Lord Kelvin's work
After James Prescott Joule had determined the mechanical equivalent of heat, Lord Kelvin approached the question from an entirely different point of view, and in 1848 devised a scale of absolute temperature that was independent of the properties of any particular substance and was based on Carnot's theory of the Motive Power of Heat and data published by Henri Victor Regnault. It followed from the principles on which this scale was constructed that its zero was placed at −273 °C, at almost precisely the same point as the zero of the air thermometer, where the air volume would reach "nothing". This value was not immediately accepted; values ranging from to , derived from laboratory measurements and observations of astronomical refraction, remained in use in the early 20th century.. |
Absolute zero | The race to absolute zero | The race to absolute zero
thumb|upright=1.2|Commemorative plaque in Leiden
With a better theoretical understanding of absolute zero, scientists were eager to reach this temperature in the lab. By 1845, Michael Faraday had managed to liquefy most gases then known to exist, and reached a new record for lowest temperatures by reaching . Faraday believed that certain gases, such as oxygen, nitrogen, and hydrogen, were permanent gases and could not be liquefied.Cryogenics. Scienceclarified.com. Retrieved on 22 July 2012. Decades later, in 1873 Dutch theoretical scientist Johannes Diderik van der Waals demonstrated that these gases could be liquefied, but only under conditions of very high pressure and very low temperatures. In 1877, Louis Paul Cailletet in France and Raoul Pictet in Switzerland succeeded in producing the first droplets of liquid air at . This was followed in 1883 by the production of liquid oxygen by the Polish professors Zygmunt Wróblewski and Karol Olszewski.
Scottish chemist and physicist James Dewar and Dutch physicist Heike Kamerlingh Onnes took on the challenge to liquefy the remaining gases, hydrogen and helium. In 1898, after 20 years of effort, Dewar was the first to liquefy hydrogen, reaching a new low-temperature record of . However, Kamerlingh Onnes, his rival, was the first to liquefy helium, in 1908, using several precooling stages and the Hampson–Linde cycle. He lowered the temperature to the boiling point of helium . By reducing the pressure of the liquid helium, he achieved an even lower temperature, near 1.5 K. These were the coldest temperatures achieved on Earth at the time and his achievement earned him the Nobel Prize in 1913. Kamerlingh Onnes would continue to study the properties of materials at temperatures near absolute zero, describing superconductivity and superfluids for the first time. |
Absolute zero | Very low temperatures | Very low temperatures
thumb|right|The rapid expansion of gases leaving the Boomerang Nebula, a bi-polar, filamentary, likely proto-planetary nebula in Centaurus, has a temperature of 1 K, the lowest observed outside of a laboratory.
The average temperature of the universe today is approximately , based on measurements of cosmic microwave background radiation. Standard models of the future expansion of the universe predict that the average temperature of the universe is decreasing over time. This temperature is calculated as the mean density of energy in space; it should not be confused with the mean electron temperature (total energy divided by particle count) which has increased over time.
Absolute zero cannot be achieved, although it is possible to reach temperatures close to it through the use of evaporative cooling, cryocoolers, dilution refrigerators, and nuclear adiabatic demagnetization. The use of laser cooling has produced temperatures of less than a billionth of a kelvin. At very low temperatures in the vicinity of absolute zero, matter exhibits many unusual properties, including superconductivity, superfluidity, and Bose–Einstein condensation. To study such phenomena, scientists have worked to obtain even lower temperatures.
In November 2000, nuclear spin temperatures below were reported for an experiment at the Helsinki University of Technology's Low Temperature Lab in Espoo, Finland. However, this was the temperature of one particular degree of freedom—a quantum property called nuclear spin—not the overall average thermodynamic temperature for all possible degrees in freedom.
In February 2003, the Boomerang Nebula was observed to have been releasing gases at a speed of for the last 1,500 years. This has cooled it down to approximately 1 K, as deduced by astronomical observation, which is the lowest natural temperature ever recorded.
In November 2003, 90377 Sedna was discovered and is one of the coldest known objects in the Solar System, with an average surface temperature of , due to its extremely far orbit of 903 astronomical units.
In May 2005, the European Space Agency proposed research in space to achieve femtokelvin temperatures.
In May 2006, the Institute of Quantum Optics at the University of Hannover gave details of technologies and benefits of femtokelvin research in space.
In January 2013, physicist Ulrich Schneider of the University of Munich in Germany reported to have achieved temperatures formally below absolute zero ("negative temperature") in gases. The gas is artificially forced out of equilibrium into a high potential energy state, which is, however, cold. When it then emits radiation it approaches the equilibrium, and can continue emitting despite reaching formal absolute zero; thus, the temperature is formally negative.
In September 2014, scientists in the CUORE collaboration at the Laboratori Nazionali del Gran Sasso in Italy cooled a copper vessel with a volume of one cubic meter to for 15 days, setting a record for the lowest temperature in the known universe over such a large contiguous volume.
In June 2015, experimental physicists at MIT cooled molecules in a gas of sodium potassium to a temperature of 500 nanokelvin, and it is expected to exhibit an exotic state of matter by cooling these molecules somewhat further.
In 2017, Cold Atom Laboratory (CAL), an experimental instrument was developed for launch to the International Space Station (ISS) in 2018. The instrument has created extremely cold conditions in the microgravity environment of the ISS leading to the formation of Bose–Einstein condensates. In this space-based laboratory, temperatures as low as are projected to be achievable, and it could further the exploration of unknown quantum mechanical phenomena and test some of the most fundamental laws of physics.
The current world record for effective temperatures was set in 2021 at through matter-wave lensing of rubidium Bose–Einstein condensates. |
Absolute zero | See also | See also
Degenerate matter
Kelvin (unit of temperature)
Charles's law
Heat
International Temperature Scale of 1990
Orders of magnitude (temperature)
Thermodynamic temperature
Triple point
Ultracold atom
Kinetic energy
Entropy
Planck temperature and Hagedorn temperature, hypothetical upper limits to the thermodynamic temperature scale |
Absolute zero | References | References |
Absolute zero | Further reading | Further reading
BIPM Mise en pratique - Kelvin - Appendix 2 - SI Brochure. |
Absolute zero | External links | External links
"Absolute zero": a two part NOVA episode originally aired January 2008
"What is absolute zero?" Lansing State Journal
Category:Cold
Category:Cryogenics
Category:Temperature |
Absolute zero | Table of Content | short description, Thermodynamics near absolute zero, Relation with Bose–Einstein condensate, Absolute temperature scales, Negative temperatures, History, Limit to the "degree of cold", Charles's law, Lord Kelvin's work, The race to absolute zero, Very low temperatures, See also, References, Further reading, External links |
Adiabatic process | Short description | An adiabatic process (adiabatic ) is a type of thermodynamic process that occurs without transferring heat between the thermodynamic system and its environment. Unlike an isothermal process, an adiabatic process transfers energy to the surroundings only as work and/or mass flow.. A translation may be found here . Also a mostly reliable translation is to be found in As a key concept in thermodynamics, the adiabatic process supports the theory that explains the first law of thermodynamics. The opposite term to "adiabatic" is diabatic.
Some chemical and physical processes occur too rapidly for energy to enter or leave the system as heat, allowing a convenient "adiabatic approximation".Bailyn, M. (1994), pp. 52–53. For example, the adiabatic flame temperature uses this approximation to calculate the upper limit of flame temperature by assuming combustion loses no heat to its surroundings.
In meteorology, adiabatic expansion and cooling of moist air, which can be triggered by winds flowing up and over a mountain for example, can cause the water vapor pressure to exceed the saturation vapor pressure. Expansion and cooling beyond the saturation vapor pressure is often idealized as a pseudo-adiabatic process whereby excess vapor instantly precipitates into water droplets. The change in temperature of an air undergoing pseudo-adiabatic expansion differs from air undergoing adiabatic expansion because latent heat is released by precipitation. |
Adiabatic process | Description | Description
A process without transfer of heat to or from a system, so that , is called adiabatic, and such a system is said to be adiabatically isolated.Münster, A. (1970), p. 48: "mass is an adiabatically inhibited variable." The simplifying assumption frequently made is that a process is adiabatic. For example, the compression of a gas within a cylinder of an engine is assumed to occur so rapidly that on the time scale of the compression process, little of the system's energy can be transferred out as heat to the surroundings. Even though the cylinders are not insulated and are quite conductive, that process is idealized to be adiabatic. The same can be said to be true for the expansion process of such a system.
The assumption of adiabatic isolation is useful and often combined with other such idealizations to calculate a good first approximation of a system's behaviour. For example, according to Laplace, when sound travels in a gas, there is no time for heat conduction in the medium, and so the propagation of sound is adiabatic. For such an adiabatic process, the modulus of elasticity (Young's modulus) can be expressed as , where is the ratio of specific heats at constant pressure and at constant volume () and is the pressure of the gas. |
Adiabatic process | Various applications of the adiabatic assumption | Various applications of the adiabatic assumption
For a closed system, one may write the first law of thermodynamics as , where denotes the change of the system's internal energy, the quantity of energy added to it as heat, and the work done by the system on its surroundings.
If the system has such rigid walls that work cannot be transferred in or out (), and the walls are not adiabatic and energy is added in the form of heat (), and there is no phase change, then the temperature of the system will rise.
If the system has such rigid walls that pressure–volume work cannot be done, but the walls are adiabatic (), and energy is added as isochoric (constant volume) work in the form of friction or the stirring of a viscous fluid within the system (), and there is no phase change, then the temperature of the system will rise.
If the system walls are adiabatic () but not rigid (), and, in a fictive idealized process, energy is added to the system in the form of frictionless, non-viscous pressure–volume work (), and there is no phase change, then the temperature of the system will rise. Such a process is called an isentropic process and is said to be "reversible". Ideally, if the process were reversed the energy could be recovered entirely as work done by the system. If the system contains a compressible gas and is reduced in volume, the uncertainty of the position of the gas is reduced, and seemingly would reduce the entropy of the system, but the temperature of the system will rise as the process is isentropic (). Should the work be added in such a way that friction or viscous forces are operating within the system, then the process is not isentropic, and if there is no phase change, then the temperature of the system will rise, the process is said to be "irreversible", and the work added to the system is not entirely recoverable in the form of work.
If the walls of a system are not adiabatic, and energy is transferred in as heat, entropy is transferred into the system with the heat. Such a process is neither adiabatic nor isentropic, having , and according to the second law of thermodynamics.
Naturally occurring adiabatic processes are irreversible (entropy is produced).
The transfer of energy as work into an adiabatically isolated system can be imagined as being of two idealized extreme kinds. In one such kind, no entropy is produced within the system (no friction, viscous dissipation, etc.), and the work is only pressure-volume work (denoted by ). In nature, this ideal kind occurs only approximately because it demands an infinitely slow process and no sources of dissipation.
The other extreme kind of work is isochoric work (), for which energy is added as work solely through friction or viscous dissipation within the system. A stirrer that transfers energy to a viscous fluid of an adiabatically isolated system with rigid walls, without phase change, will cause a rise in temperature of the fluid, but that work is not recoverable. Isochoric work is irreversible. The second law of thermodynamics observes that a natural process, of transfer of energy as work, always consists at least of isochoric work and often both of these extreme kinds of work. Every natural process, adiabatic or not, is irreversible, with , as friction or viscosity are always present to some extent. |
Adiabatic process | Adiabatic compression and expansion | Adiabatic compression and expansion
The adiabatic compression of a gas causes a rise in temperature of the gas. Adiabatic expansion against pressure, or a spring, causes a drop in temperature. In contrast, free expansion is an isothermal process for an ideal gas.
Adiabatic compression occurs when the pressure of a gas is increased by work done on it by its surroundings, e.g., a piston compressing a gas contained within a cylinder and raising the temperature where in many practical situations heat conduction through walls can be slow compared with the compression time. This finds practical application in diesel engines which rely on the lack of heat dissipation during the compression stroke to elevate the fuel vapor temperature sufficiently to ignite it.
Adiabatic compression occurs in the Earth's atmosphere when an air mass descends, for example, in a Katabatic wind, Foehn wind, or Chinook wind flowing downhill over a mountain range. When a parcel of air descends, the pressure on the parcel increases. Because of this increase in pressure, the parcel's volume decreases and its temperature increases as work is done on the parcel of air, thus increasing its internal energy, which manifests itself by a rise in the temperature of that mass of air. The parcel of air can only slowly dissipate the energy by conduction or radiation (heat), and to a first approximation it can be considered adiabatically isolated and the process an adiabatic process.
Adiabatic expansion occurs when the pressure on an adiabatically isolated system is decreased, allowing it to expand in size, thus causing it to do work on its surroundings. When the pressure applied on a parcel of gas is reduced, the gas in the parcel is allowed to expand; as the volume increases, the temperature falls as its internal energy decreases. Adiabatic expansion occurs in the Earth's atmosphere with orographic lifting and lee waves, and this can form pilei or lenticular clouds.
Due in part to adiabatic expansion in mountainous areas, snowfall infrequently occurs in some parts of the Sahara desert.
Adiabatic expansion does not have to involve a fluid. One technique used to reach very low temperatures (thousandths and even millionths of a degree above absolute zero) is via adiabatic demagnetisation, where the change in magnetic field on a magnetic material is used to provide adiabatic expansion. Also, the contents of an expanding universe can be described (to first order) as an adiabatically expanding fluid. (See heat death of the universe.)
Rising magma also undergoes adiabatic expansion before eruption, particularly significant in the case of magmas that rise quickly from great depths such as kimberlites.
In the Earth's convecting mantle (the asthenosphere) beneath the lithosphere, the mantle temperature is approximately an adiabat. The slight decrease in temperature with shallowing depth is due to the decrease in pressure the shallower the material is in the Earth.
Such temperature changes can be quantified using the ideal gas law, or the hydrostatic equation for atmospheric processes.
In practice, no process is truly adiabatic. Many processes rely on a large difference in time scales of the process of interest and the rate of heat dissipation across a system boundary, and thus are approximated by using an adiabatic assumption. There is always some heat loss, as no perfect insulators exist. |
Adiabatic process | Ideal gas (reversible process) | Ideal gas (reversible process)
thumb|upright=1.2|For a simple substance, during an adiabatic process in which the volume increases, the internal energy of the working substance must decrease.
The mathematical equation for an ideal gas undergoing a reversible (i.e., no entropy generation) adiabatic process can be represented by the polytropic process equation
where is pressure, is volume, and is the adiabatic index or heat capacity ratio defined as
Here is the specific heat for constant pressure, is the specific heat for constant volume, and is the number of degrees of freedom (3 for a monatomic gas, 5 for a diatomic gas or a gas of linear molecules such as carbon dioxide).
For a monatomic ideal gas, , and for a diatomic gas (such as nitrogen and oxygen, the main components of air), . Note that the above formula is only applicable to classical ideal gases (that is, gases far above absolute zero temperature) and not Bose–Einstein or Fermi gases.
One can also use the ideal gas law to rewrite the above relationship between and as
where T is the absolute or thermodynamic temperature. |
Adiabatic process | Example of adiabatic compression | Example of adiabatic compression
The compression stroke in a gasoline engine can be used as an example of adiabatic compression. The model assumptions are: the uncompressed volume of the cylinder is one litre (1 L = 1000 cm3 = 0.001 m3); the gas within is the air consisting of molecular nitrogen and oxygen only (thus a diatomic gas with 5 degrees of freedom, and so ); the compression ratio of the engine is 10:1 (that is, the 1 L volume of uncompressed gas is reduced to 0.1 L by the piston); and the uncompressed gas is at approximately room temperature and pressure (a warm room temperature of ~27 °C, or 300 K, and a pressure of 1 bar = 100 kPa, i.e. typical sea-level atmospheric pressure).
so the adiabatic constant for this example is about
The gas is now compressed to a 0.1 L (0.0001 m3) volume, which we assume happens quickly enough that no heat enters or leaves the gas through the walls. The adiabatic constant remains the same, but with the resulting pressure unknown
We can now solve for the final pressure
or 25.1 bar. This pressure increase is more than a simple 10:1 compression ratio would indicate; this is because the gas is not only compressed, but the work done to compress the gas also increases its internal energy, which manifests itself by a rise in the gas temperature and an additional rise in pressure above what would result from a simplistic calculation of 10 times the original pressure.
We can solve for the temperature of the compressed gas in the engine cylinder as well, using the ideal gas law, PV = nRT (n is amount of gas in moles and R the gas constant for that gas). Our initial conditions being 100 kPa of pressure, 1 L volume, and 300 K of temperature, our experimental constant (nR) is:
We know the compressed gas has = 0.1 L and = , so we can solve for temperature:
That is a final temperature of 753 K, or 479 °C, or 896 °F, well above the ignition point of many fuels. This is why a high-compression engine requires fuels specially formulated to not self-ignite (which would cause engine knocking when operated under these conditions of temperature and pressure), or that a supercharger with an intercooler to provide a pressure boost but with a lower temperature rise would be advantageous. A diesel engine operates under even more extreme conditions, with compression ratios of 16:1 or more being typical, in order to provide a very high gas pressure, which ensures immediate ignition of the injected fuel. |
Adiabatic process | Adiabatic free expansion of a gas | Adiabatic free expansion of a gas
For an adiabatic free expansion of an ideal gas, the gas is contained in an insulated container and then allowed to expand in a vacuum. Because there is no external pressure for the gas to expand against, the work done by or on the system is zero. Since this process does not involve any heat transfer or work, the first law of thermodynamics then implies that the net internal energy change of the system is zero. For an ideal gas, the temperature remains constant because the internal energy only depends on temperature in that case. Since at constant temperature, the entropy is proportional to the volume, the entropy increases in this case, therefore this process is irreversible. |
Adiabatic process | Derivation of ''P''–''V'' relation for adiabatic compression and expansion | Derivation of P–V relation for adiabatic compression and expansion
The definition of an adiabatic process is that heat transfer to the system is zero, . Then, according to the first law of thermodynamics,
where is the change in the internal energy of the system and is work done by the system. Any work () done must be done at the expense of internal energy , since no heat is being supplied from the surroundings. Pressure–volume work done by the system is defined as
However, does not remain constant during an adiabatic process but instead changes along with .
It is desired to know how the values of and relate to each other as the adiabatic process proceeds. For an ideal gas (recall ideal gas law ) the internal energy is given by
where is the number of degrees of freedom divided by 2, is the universal gas constant and is the number of moles in the system (a constant).
Differentiating equation (a3) yields
Equation (a4) is often expressed as because .
Now substitute equations (a2) and (a4) into equation (a1) to obtain
factorize :
and divide both sides by :
After integrating the left and right sides from to and from to and changing the sides respectively,
Exponentiate both sides, substitute with , the heat capacity ratio
and eliminate the negative sign to obtain
Therefore,
and
At the same time, the work done by the pressure–volume changes as a result from this process, is equal to
Since we require the process to be adiabatic, the following equation needs to be true
By the previous derivation,
Rearranging (b4) gives
Substituting this into (b2) gives
Integrating, we obtain the expression for work,
Substituting in the second term,
Rearranging,
Using the ideal gas law and assuming a constant molar quantity (as often happens in practical cases),
By the continuous formula,
or
Substituting into the previous expression for ,
Substituting this expression and (b1) in (b3) gives
Simplifying, |
Adiabatic process | Derivation of discrete formula and work expression | Derivation of discrete formula and work expression
The change in internal energy of a system, measured from state 1 to state 2, is equal to
At the same time, the work done by the pressure–volume changes as a result from this process, is equal to
Since we require the process to be adiabatic, the following equation needs to be true
By the previous derivation,
Rearranging (c4) gives
Substituting this into (c2) gives
Integrating we obtain the expression for work,
Substituting in second term,
Rearranging,
Using the ideal gas law and assuming a constant molar quantity (as often happens in practical cases),
By the continuous formula,
or
Substituting into the previous expression for ,
Substituting this expression and (c1) in (c3) gives
Simplifying, |
Adiabatic process | Graphing adiabats | Graphing adiabats
thumb|upright=1.6|P–V diagram with a superposition of adiabats and isotherms:
An adiabat is a curve of constant entropy in a diagram. Some properties of adiabats on a P–V diagram are indicated. These properties may be read from the classical behaviour of ideal gases, except in the region where PV becomes small (low temperature), where quantum effects become important.
Every adiabat asymptotically approaches both the V axis and the P axis (just like isotherms).
Each adiabat intersects each isotherm exactly once.
An adiabat looks similar to an isotherm, except that during an expansion, an adiabat loses more pressure than an isotherm, so it has a steeper inclination (more vertical).
If isotherms are concave towards the north-east direction (45° from V-axis), then adiabats are concave towards the east north-east (31° from V-axis).
If adiabats and isotherms are graphed at regular intervals of entropy and temperature, respectively (like altitude on a contour map), then as the eye moves towards the axes (towards the south-west), it sees the density of isotherms stay constant, but it sees the density of adiabats grow. The exception is very near absolute zero, where the density of adiabats drops sharply and they become rare (see Nernst's theorem). |
Adiabatic process | Etymology | Etymology
The term adiabatic () is an anglicization of the Greek term ἀδιάβατος "impassable" (used by Xenophon of rivers). It is used in the thermodynamic sense by Rankine (1866),Rankine, William John MacQuorn (1866). On the theory of explosive gas engines, The Engineer, July 27, 1866; at page 467 of the reprint in Miscellaneous Scientific Papers, edited by W. J. Millar, 1881, Charles Griffin, London. and adopted by Maxwell in 1871 (explicitly attributing the term to Rankine).
The etymological origin corresponds here to an impossibility of transfer of energy as heat and of transfer of matter across the wall.
The Greek word ἀδιάβατος is formed from privative ἀ- ("not") and διαβατός, "passable", in turn deriving from διά ("through"), and βαῖνειν ("to walk, go, come").Liddell, H. G., Scott, R. (1940). A Greek-English Lexicon, Clarendon Press, Oxford, UK.
Furthermore, in atmospheric thermodynamics, a diabatic process is one in which heat is exchanged. An adiabatic process is the opposite – a process in which no heat is exchanged. |
Adiabatic process | Conceptual significance in thermodynamic theory | Conceptual significance in thermodynamic theory
The adiabatic process has been important for thermodynamics since its early days. It was important in the work of Joule because it provided a way of nearly directly relating quantities of heat and work.
Energy can enter or leave a thermodynamic system enclosed by walls that prevent mass transfer only as heat or work. Therefore, a quantity of work in such a system can be related almost directly to an equivalent quantity of heat in a cycle of two limbs. The first limb is an isochoric adiabatic work process increasing the system's internal energy; the second, an isochoric and workless heat transfer returning the system to its original state. Accordingly, Rankine measured quantity of heat in units of work, rather than as a calorimetric quantity. Miscellaneous Scientific Papers p. 339 In 1854, Rankine used a quantity that he called "the thermodynamic function" that later was called entropy, and at that time he wrote also of the "curve of no transmission of heat", Miscellaneous Scientific Papers p. 341. which he later called an adiabatic curve. Besides its two isothermal limbs, Carnot's cycle has two adiabatic limbs.
For the foundations of thermodynamics, the conceptual importance of this was emphasized by Bryan, by Carathéodory, and by Born. The reason is that calorimetry presupposes a type of temperature as already defined before the statement of the first law of thermodynamics, such as one based on empirical scales. Such a presupposition involves making the distinction between empirical temperature and absolute temperature. Rather, the definition of absolute thermodynamic temperature is best left till the second law is available as a conceptual basis.
In the eighteenth century, the law of conservation of energy was not yet fully formulated or established, and the nature of heat was debated. One approach to these problems was to regard heat, measured by calorimetry, as a primary substance that is conserved in quantity. By the middle of the nineteenth century, it was recognized as a form of energy, and the law of conservation of energy was thereby also recognized. The view that eventually established itself, and is currently regarded as right, is that the law of conservation of energy is a primary axiom, and that heat is to be analyzed as consequential. In this light, heat cannot be a component of the total energy of a single body because it is not a state variable but, rather, a variable that describes a transfer between two bodies. The adiabatic process is important because it is a logical ingredient of this current view. |
Adiabatic process | Divergent usages of the word ''adiabatic'' | Divergent usages of the word adiabatic
This present article is written from the viewpoint of macroscopic thermodynamics, and the word adiabatic is used in this article in the traditional way of thermodynamics, introduced by Rankine. It is pointed out in the present article that, for example, if a compression of a gas is rapid, then there is little time for heat transfer to occur, even when the gas is not adiabatically isolated by a definite wall. In this sense, a rapid compression of a gas is sometimes approximately or loosely said to be adiabatic, though often far from isentropic, even when the gas is not adiabatically isolated by a definite wall.
Some authors, like Pippard, recommend using "adiathermal" to refer to processes where no heat-exchange occurs (such as Joule expansion), and "adiabatic" to reversible quasi-static adiathermal processes (so that rapid compression of a gas is not "adiabatic"). And Laidler has summarized the complicated etymology of "adiabatic".
Quantum mechanics and quantum statistical mechanics, however, use the word adiabatic in a very different sense, one that can at times seem almost opposite to the classical thermodynamic sense. In quantum theory, the word adiabatic can mean something perhaps near isentropic, or perhaps near quasi-static, but the usage of the word is very different between the two disciplines.
On the one hand, in quantum theory, if a perturbative element of compressive work is done almost infinitely slowly (that is to say quasi-statically), it is said to have been done adiabatically. The idea is that the shapes of the eigenfunctions change slowly and continuously, so that no quantum jump is triggered, and the change is virtually reversible. While the occupation numbers are unchanged, nevertheless there is change in the energy levels of one-to-one corresponding, pre- and post-compression, eigenstates. Thus a perturbative element of work has been done without heat transfer and without introduction of random change within the system. For example, Max Born writes
On the other hand, in quantum theory, if a perturbative element of compressive work is done rapidly, it changes the occupation numbers and energies of the eigenstates in proportion to the transition moment integral and in accordance with time-dependent perturbation theory, as well as perturbing the functional form of the eigenstates themselves. In that theory, such a rapid change is said not to be adiabatic, and the contrary word diabatic is applied to it.
Recent research suggests that the power absorbed from the perturbation corresponds to the rate of these non-adiabatic transitions. This corresponds to the classical process of energy transfer in the form of heat, but with the relative time scales reversed in the quantum case. Quantum adiabatic processes occur over relatively long time scales, while classical adiabatic processes occur over relatively short time scales. It should also be noted that the concept of 'heat' (in reference to the quantity of thermal energy transferred) breaks down at the quantum level, and the specific form of energy (typically electromagnetic) must be considered instead. The small or negligible absorption of energy from the perturbation in a quantum adiabatic process provides a good justification for identifying it as the quantum analogue of adiabatic processes in classical thermodynamics, and for the reuse of the term.
In classical thermodynamics, such a rapid change would still be called adiabatic because the system is adiabatically isolated, and there is no transfer of energy as heat. The strong irreversibility of the change, due to viscosity or other entropy production, does not impinge on this classical usage.
Thus for a mass of gas, in macroscopic thermodynamics, words are so used that a compression is sometimes loosely or approximately said to be adiabatic if it is rapid enough to avoid significant heat transfer, even if the system is not adiabatically isolated. But in quantum statistical theory, a compression is not called adiabatic if it is rapid, even if the system is adiabatically isolated in the classical thermodynamic sense of the term. The words are used differently in the two disciplines, as stated just above. |
Adiabatic process | See also | See also
Fire piston
Heat burst
Related physics topics
First law of thermodynamics
Entropy (classical thermodynamics)
Adiabatic conductivity
Adiabatic lapse rate
Total air temperature
Magnetic refrigeration
Berry phase
Related thermodynamic processes
Cyclic process
Isobaric process
Isenthalpic process
Isentropic process
Isochoric process
Isothermal process
Polytropic process
Quasistatic process |
Adiabatic process | References | References
General
Nave, Carl Rod. "Adiabatic Processes". HyperPhysics.
Thorngren, Dr. Jane R. "Adiabatic Processes". Daphne – A Palomar College Web Server, 21 July 1995. . |
Adiabatic process | External links | External links
Article in HyperPhysics Encyclopaedia
Category:Thermodynamic processes
Category:Atmospheric thermodynamics
Category:Entropy |
Adiabatic process | Table of Content | Short description, Description, Various applications of the adiabatic assumption, Adiabatic compression and expansion, Ideal gas (reversible process), Example of adiabatic compression, Adiabatic free expansion of a gas, Derivation of ''P''–''V'' relation for adiabatic compression and expansion, Derivation of discrete formula and work expression, Graphing adiabats, Etymology, Conceptual significance in thermodynamic theory, Divergent usages of the word ''adiabatic'', See also, References, External links |
Amide | short description | thumb|right|General structure of an amide (specifically, a carboxamide)
thumb|right|Formamide, the simplest amide
thumb|right|Asparagine (zwitterionic form), an amino acid with a side chain (highlighted) containing an amide group
In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, as in asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid () with the hydroxyl group () replaced by an amino group (); or, equivalently, an acyl (alkanoyl) group () joined to an amino group.
Common of amides are formamide (), acetamide (), benzamide (), and dimethylformamide (). Some uncommon examples of amides are N-chloroacetamide () and chloroformamide ().
Amides are qualified as primary, secondary, and tertiary according to the number of acyl groups bounded to the nitrogen atom. |
Amide | Nomenclature | Nomenclature
The core of amides is called the amide group (specifically, carboxamide group).
In the usual nomenclature, one adds the term "amide" to the stem of the parent acid's name. For instance, the amide derived from acetic acid is named acetamide (CH3CONH2). IUPAC recommends ethanamide, but this and related formal names are rarely encountered. When the amide is derived from a primary or secondary amine, the substituents on nitrogen are indicated first in the name. Thus, the amide formed from dimethylamine and acetic acid is N,N-dimethylacetamide (CH3CONMe2, where Me = CH3). Usually even this name is simplified to dimethylacetamide. Cyclic amides are called lactams; they are necessarily secondary or tertiary amides. Full text (PDF) of Draft Rule P-66: Amides, Imides, Hydrazides, Nitriles, Aldehydes, Their Chalcogen Analogues, and Derivatives |
Amide | Applications | Applications
Amides are pervasive in nature and technology. Proteins and important plastics like nylons, aramids, Twaron, and Kevlar are polymers whose units are connected by amide groups (polyamides); these linkages are easily formed, confer structural rigidity, and resist hydrolysis. Amides include many other important biological compounds, as well as many drugs like paracetamol, penicillin and LSD. Low-molecular-weight amides, such as dimethylformamide, are common solvents. |
Amide | Structure and bonding | Structure and bonding
thumb|288 px|Structure of acetamide hydrogen-bonded dimer from X-ray crystallography. Selected distances: C-O: 1.243, C-N, 1.325, N---O, 2.925 Å. Color code: red = O, blue = N, gray = C, white = H.
The lone pair of electrons on the nitrogen atom is delocalized into the Carbonyl group, thus forming a partial double bond between nitrogen and carbon. In fact the O, C and N atoms have molecular orbitals occupied by delocalized electrons, forming a conjugated system. Consequently, the three bonds of the nitrogen in amides is not pyramidal (as in the amines) but planar. This planar restriction prevents rotations about the N linkage and thus has important consequences for the mechanical properties of bulk material of such molecules, and also for the configurational properties of macromolecules built by such bonds. The inability to rotate distinguishes amide groups from ester groups which allow rotation and thus create more flexible bulk material.
The C-C(O)NR2 core of amides is planar. The C=O distance is shorter than the C-N distance by almost 10%. The structure of an amide can be described also as a resonance between two alternative structures: neutral (A) and zwitterionic (B).
300px|thumb|none
It is estimated that for acetamide, structure A makes a 62% contribution to the structure, while structure B makes a 28% contribution (these figures do not sum to 100% because there are additional less-important resonance forms that are not depicted above). There is also a hydrogen bond present between the hydrogen and nitrogen atoms in the active groups. Resonance is largely prevented in the very strained quinuclidone.
In their IR spectra, amides exhibit a moderately intense νCO band near 1650 cm−1. The energy of this band is about 60 cm−1 lower than for the νCO of esters and ketones. This difference reflects the contribution of the zwitterionic resonance structure. |
Amide | Basicity | Basicity
Compared to amines, amides are very weak bases. While the conjugate acid of an amine has a pKa of about 9.5, the conjugate acid of an amide has a pKa around −0.5. Therefore, compared to amines, amides do not have acid–base properties that are as noticeable in water. This relative lack of basicity is explained by the withdrawing of electrons from the amine by the carbonyl. On the other hand, amides are much stronger bases than carboxylic acids, esters, aldehydes, and ketones (their conjugate acids' pKas are between −6 and −10).
The proton of a primary or secondary amide does not dissociate readily; its pKa is usually well above 15. Conversely, under extremely acidic conditions, the carbonyl oxygen can become protonated with a pKa of roughly −1. It is not only because of the positive charge on the nitrogen but also because of the negative charge on the oxygen gained through resonance. |
Amide | Hydrogen bonding and solubility | Hydrogen bonding and solubility
Because of the greater electronegativity of oxygen than nitrogen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. In primary and secondary amides, the presence of N–H dipoles allows amides to function as H-bond donors as well. Thus amides can participate in hydrogen bonding with water and other protic solvents; the oxygen atom can accept hydrogen bonds from water and the N–H hydrogen atoms can donate H-bonds. As a result of interactions such as these, the water solubility of amides is greater than that of corresponding hydrocarbons. These hydrogen bonds also have an important role in the secondary structure of proteins.
The solubilities of amides and esters are roughly comparable. Typically amides are less soluble than comparable amines and carboxylic acids since these compounds can both donate and accept hydrogen bonds. Tertiary amides, with the important exception of N,N-dimethylformamide, exhibit low solubility in water. |
Amide | Reactions | Reactions
Amides do not readily participate in nucleophilic substitution reactions. Amides are stable to water, and are roughly 100 times more stable towards hydrolysis than esters. Amides can, however, be hydrolyzed to carboxylic acids in the presence of acid or base. The stability of amide bonds has biological implications, since the amino acids that make up proteins are linked with amide bonds. Amide bonds are resistant enough to hydrolysis to maintain protein structure in aqueous environments but are susceptible to catalyzed hydrolysis.
Primary and secondary amides do not react usefully with carbon nucleophiles. Instead, Grignard reagents and organolithiums deprotonate an amide N-H bond. Tertiary amides do not experience this problem, and react with carbon nucleophiles to give ketones; the amide anion (NR2−) is a very strong base and thus a very poor leaving group, so nucleophilic attack only occurs once. When reacted with carbon nucleophiles, N,N-dimethylformamide (DMF) can be used to introduce a formyl group.
900px|Because tertiary amides only react once with organolithiums, they can be used to introduce aldehyde and ketone functionalities. Here, DMF serves as a source of the formyl group in the synthesis of benzaldehyde.|thumb|none
Here, phenyllithium 1 attacks the carbonyl group of DMF 2, giving tetrahedral intermediate 3. Because the dimethylamide anion is a poor leaving group, the intermediate does not collapse and another nucleophilic addition does not occur. Upon acidic workup, the alkoxide is protonated to give 4, then the amine is protonated to give 5. Elimination of a neutral molecule of dimethylamine and loss of a proton give benzaldehyde, 6.
320 px|thumb|Mechanism for acid-mediated hydrolysis of an amide. |
Amide | Hydrolysis | Hydrolysis
Amides hydrolyse in hot alkali as well as in strong acidic conditions. Acidic conditions yield the carboxylic acid and the ammonium ion while basic hydrolysis yield the carboxylate ion and ammonia. The protonation of the initially generated amine under acidic conditions and the deprotonation of the initially generated carboxylic acid under basic conditions render these processes non-catalytic and irreversible. Electrophiles other than protons react with the carbonyl oxygen. This step often precedes hydrolysis, which is catalyzed by both Brønsted acids and Lewis acids. Peptidase enzymes and some synthetic catalysts often operate by attachment of electrophiles to the carbonyl oxygen.
Reaction name Product Comment DehydrationNitrile Reagent: phosphorus pentoxide; benzenesulfonyl chloride; TFAA/py Hofmann rearrangementAmine with one fewer carbon atomReagents: bromine and sodium hydroxide Amide reduction Amines, aldehydesReagent: lithium aluminium hydride followed by hydrolysisVilsmeier–Haack reactionAldehyde (via imine) , aromatic substrate, formamideBischler–Napieralski reactionCyclic aryl imine , , etc.Tautomeric chlorinationImidoyl chlorideOxophilic halogenating agents, e.g. COCl2 or SOCl2 |
Amide | Synthesis | Synthesis |
Amide | From carboxylic acids and related compounds | From carboxylic acids and related compounds
Amides are usually prepared by coupling a carboxylic acid with an amine. The direct reaction generally requires high temperatures to drive off the water:
Esters are far superior substrates relative to carboxylic acids.
Further "activating" both acid chlorides (Schotten-Baumann reaction) and anhydrides (Lumière–Barbier method) react with amines to give amides:
Peptide synthesis use coupling agents such as HATU, HOBt, or PyBOP. |
Amide | From nitriles | From nitriles
The hydrolysis of nitriles is conducted on an industrial scale to produce fatty amides. Laboratory procedures are also available. |
Amide | Specialty routes | Specialty routes
Many specialized methods also yield amides. A variety of reagents, e.g. tris(2,2,2-trifluoroethyl) borate have been developed for specialized applications.
+ Specialty Routes to AmidesReaction name Substrate Details Beckmann rearrangementCyclic ketone Reagent: hydroxylamine and acid Schmidt reactionKetones Reagent: hydrazoic acid Willgerodt–Kindler reaction Aryl alkyl ketones Sulfur and morpholinePasserini reaction Carboxylic acid, ketone or aldehydeUgi reaction Isocyanide, carboxylic acid, ketone, primary amineBodroux reaction Carboxylic acid, Grignard reagent with an aniline derivative ArNHR' 400pxChapman rearrangementAryl imino etherFor N,N-diaryl amides. The reaction mechanism is based on a nucleophilic aromatic substitution. Leuckart amide synthesis Isocyanate Reaction of arene with isocyanate catalysed by aluminium trichloride, formation of aromatic amide. Ritter reaction Alkenes, alcohols, or other carbonium ion sources Secondary amides via an addition reaction between a nitrile and a carbonium ion in the presence of concentrated acids. Photolytic addition of formamide to olefins Terminal alkenes A free radical homologation reaction between a terminal alkene and formamide.Dehydrogenative couplingalcohol, amine requires ruthenium dehydrogenation catalystTransamidationamidetypically slow |