Johann Georg Anton Geuther (23 April 1833 – 23 August 1889) was a German

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe ...

. His work in organic and inorganic chemistry influenced the development of

coordination chemistry A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of chemical bond, bound molecules or ions, that are in turn known as ''ligands'' or complexing ...

. Geuther spent most of his academic career at the

University of Jena The University of Jena, officially the Friedrich Schiller University Jena (german: Friedrich-Schiller-Universität Jena, abbreviated FSU, shortened form ''Uni Jena''), is a public research university located in Jena, Thuringia, Germany. The un ...

where he discovered

ethyl acetoacetate The organic compound ethyl acetoacetate (EAA) is the ethyl ester of acetoacetic acid. It is a colorless liquid. It is widely used as a chemical intermediate in the production of a wide variety of compounds. It is used as a flavoring for food. Pr ...

, a key compound for chemical synthesis and for the discovery of

tautomerism Tautomers () are structural isomers (constitutional isomers) of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hydr ...

Life

Geuther was born in

Neustadt bei Coburg Neustadt bei Coburg (also written ''Neustadt b. Coburg'') is a town in the district of Coburg in northern Bavaria, Germany. It is situated 15 km northeast of Coburg, as its name indicates. Local subdivisions Neustadt bei Coburg is subdivide ...

and was educated in Neustad,

Coburg Coburg () is a town located on the Itz river in the Upper Franconia region of Bavaria, Germany. Long part of one of the Thuringian states of the Wettin line, it joined Bavaria by popular vote only in 1920. Until the revolution of 1918, it ...

and

Saalfeld Saalfeld (german: Saalfeld/Saale) is a town in Germany, capital of the Saalfeld-Rudolstadt district of Thuringia. It is best known internationally as the ancestral seat of the Saxe-Coburg and Gotha branch of the Saxon House of Wettin. Geography ...

. Although his family favoured education in the merchant business, he started to study chemistry at the University of Jena, but changed to the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded i ...

in 1853. He received his PhD in 1855 for a work on

oil shale Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitu ...

carried out together with

Friedrich Wöhler Friedrich Wöhler () FRS(For) HonFRSE (31 July 180023 September 1882) was a German chemist known for his work in inorganic chemistry, being the first to isolate the chemical elements beryllium and yttrium in pure metallic form. He was the first ...

. In the following years, he gradually improved his position in Göttingen and became professor in the

in 1860. In 1883 he married and lived until his death with his wife, son and daughter in Jena. Geuther died of

typhus Typhus, also known as typhus fever, is a group of infectious diseases that include epidemic typhus, scrub typhus, and murine typhus. Common symptoms include fever, headache, and a rash. Typically these begin one to two weeks after exposure. ...

in 1889 at the age of 57.

Work

Geuther started to work on inorganic topics, such as the electrolysis of

chromic acid The term chromic acid is usually used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide. This kind of chromic acid may be used as a cleaning mixt ...

and sulfuric acid to determine the similarities of the two compounds. His research on the constitution of several cobalt

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent su ...

complexes, such as

hexamminecobalt(III) chloride Hexaamminecobalt(III) chloride is the chemical compound with the formula o(NH3)6l3. It is the chloride salt of the coordination complex o(NH3)6+, which is considered an archetypal "Werner complex", named after the pioneer of coordination ...

, were later completed by

Alfred Werner Alfred Werner (12 December 1866 – 15 November 1919) was a Swiss chemist who was a student at ETH Zurich and a professor at the University of Zurich. He won the Nobel Prize in Chemistry in 1913 for proposing the octahedral configuration o ...

earning Werner a

Nobel Prize in Chemistry ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then "M ...

. Some of his organic research was connected to

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. ...

ism of chemical molecules. The experimental work on the

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis ...

1,1-dichloroethane 1,1-Dichloroethane is a chlorinated hydrocarbon. It is a colorless oily liquid with a chloroform-like odor. It is not easily soluble in water, but miscible with most organic solvents. Large volumes of 1,1-dichloroethane are manufactured, with ...

, which yielded

glycol A diol is a chemical compound containing two hydroxyl groups ( groups). An aliphatic diol is also called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. The most common industrial diol is e ...

, and the chlorination of

acetaldehyde Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3 CHO, sometimes abbreviated by chemists as MeCHO (Me = methyl). It is a colorless liquid or gas, boiling near room temperature. It is one of the ...

giving

1,2-dichloroethane The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vin ...

provided a good starting point for the development of the theory of the constitution of compounds with the same chemical formula, but different bond structure. Beta-keto_acid_tautomerism

Geuther is best known for his discovery of

. Although he discovered the compound in 1863, it took him two years to publish results in a peer reviewed journal. The experimental work of his and others yielded puzzling results and induced debates on the nature of ethyl acetoacetate. The structure proposed by

Edward Frankland Sir Edward Frankland, (18 January 18259 August 1899) was an English chemist. He was one of the originators of organometallic chemistry and introduced the concept of combining power or valence. An expert in water quality and analysis, he was ...

and Duppa showed a

keto group In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety of carbon-containing substituents. Ketones contain a carbonyl group –C(=O)– (which contains a carbon-oxygen double bon ...

(C=O), while Geuther was certain about presence of an acidic OH group in the molecule. It was long after the death of Geuther when

Ludwig Knorr Ludwig Knorr (2 December 1859 – 4 June 1921) was a German chemist. Together with Carl Paal, he discovered the Paal–Knorr synthesis, and the Knorr quinoline synthesis and Knorr pyrrole synthesis are also named after him. The synthesis in 1 ...

, Geuthers successor at the

, solved the riddle proving both sides right: the true nature of ethyl acetoacetate was a tautomeric equilibrium between the both suggested structures. The

Keto-enol tautomerism In organic chemistry, alkenols (shortened to enols) are a type of reactive structure or intermediate in organic chemistry that is represented as an alkene ( olefin) with a hydroxyl group attached to one end of the alkene double bond (). The t ...

strongly depends on the solvent used for the experiments. Geuther was planning to build a new chemical laboratory at University of Jena, but died well before the construction had started. Some of his unfinished work was completed by his successor in Jena

References

{{DEFAULTSORT:Geuther, Johann Georg Anton 1833 births 1889 deaths 19th-century German chemists University of Jena faculty University of Göttingen alumni People from Coburg (district)