Curtius

NAME: Curtius, Theodore

ACHIEVEMENT(S): Researched  nitrogen-containing organic substances, discovering two important chemical reactions (named for him) and the compound hydrazine.

NICKNAME/ALIAS: None

DATE/PLACE OF BIRTH: 27 May 1857, at Duisberg, Germany

DATE/PLACE/AGE AT DEATH: 8 February 1928, at Heidelberg, Germany.  Aged 70

DISCIPLINE: Chemist

FIELD: Chemistry

LANGUAGE: German

PARENTS: Julius Curtius (1818-85) and Sophie Ohlenschlager (1828-90)

SIBLINGS: Unknown

SPOUSE: None

CHILDREN: None

EDUCATION: Duisberg Gymnasium to 1876; University of Heidelberg, 1878-82

MAJOR WORK: "Uber das Diamid (Hydrazin)", 1887

LIFE AND TIMES: Theodor Curtius was the son of Julius Curtius, whose own father, Friedrich Wilhelm Curtius, was a manufacturer of inorganic chemicals. At Leipzig for a year he studied music and science.

He then served his year's military service (1877-78), during which he became a first lieutenant, and then in 1878  entered the University of Heidelberg, where he studied chemistry under Bunsen*, receiving his B.S. degree in 1880. 

He moved to the University of Leipzig, where under Hermann Kolbe he investigated the synthesis of hippuric acid (an amide of glycine, the simplest amino acid) as his doctoral research.  

After receiving his Ph.D. in July 1882, Curtius worked in the chemical laboratory of Baeyer* at the University of Munich, where he continued his studies of hippuric acid.

On Baeyer's suggestion, Curtius then began investigating the ethyl ester of glycine, and in 1886 discovered that when treated with sodium nitrate and hydrochloric acid, it produced the first known aliphatic diazo compound, diazoacetic ester.  

Later in 1886, Curtius was appointed assistant and director of the analytical section of the chemical laboratories of the University of Erlangen, where in 1887 he treated the ethyl diazoacetate with concentrated sodium hydroxide, added hot dilute acid to the product, and so discovered hydrazine*, a highly volatile, colourless liquid with an ammonia-like odour.

In 1890, Curtius then discovered hydrazoic acid (HN3), by treating benzoyl and hippuryl derivatives of hydrazine with nitrous acid.  Continuing these experiments, in 1893 Curtius discovered that hydrazoic acid is produced by the action of red fuming nitric acid on a dilute, ice-cold solution of hydrazine. (In 1908, a commercial process for producing hydrazine was developed by Friedrich Raschig, involving the reaction of an aqueous alkaline ammonia solution with sodium hypochlorite in the presence of gelatin, which was later used in Germany during World War II for the production of hydrazine for use as rocket fuel). 

In 1894, while still at Erlangen, Curtius discovered the first of the two reactions later named for him - the conversion of an acid into the corresponding amine, by way of the azide and urethane. (He later varied the procedure,  and in 1906 was able to produce the corresponding aldehyde in place of the amine).

In 1913, he discovered the second reaction to carry his name - that when an acyl azide (a compound prepared by a reaction of nitrous acid and acid hydrazides) is heated, its molecular structure is altered to form an isocyanate (a compound having the functional group NCO), and that in the presence of water the isocyanate is converted to an amine containing one less carbon atom than the acyl azide. 

Meanwhile, from 1882 onwards Curtius had also been researching certain organic compounds which were later named polypeptides (by Fischer*, in 1906). Using diazo compounds as intermediates (i.e. as substances produced during the conversion of a reactant to a product), he synthesized benzoyl derivatives of amino acids, and in 1904 he succeeded in synthesizing a hexapeptide - benzoyl pentaglycine-aminoacetic acid - by fusing ethyl hippurate with glycine.

He also investigated the rearrangement of aliphatic ketazines and aldazines into pyrazoline derivatives, prepared azides and hydrazides of acids, and obtained benzyl hydrazine from the reduction of benzaldazine. 

In 1897, Curtius succeeded Kekule* as professor of chemistry at the University of Bonn, but the following year he returned to the University of Heidelberg, where he succeeded Viktor Mayer. 

Curtius remained at Heidelberg for the rest of his career, as director of the chemical institute and editor of the Journal of Applied Chemistry. In 1912, he began investigating plant chemistry with Hartwig Franzen, and together they discovered hexenal but no formaldehyde (or methanal) in green plants, which led Baeyer to abandon his hypothesis that hexoses are built up from the condensation of hydrated formaldehyde within the plant tissues.

Curtius retired from the chemical institute in 1926, and died at Heidelberg two years later  Curtius's discovery of hydrazine (N2H4) was perhaps the most important of his achievements, as the compound has uses in the modern world.

Hydrazine is a compound that reacts with acids and some metallic salts to produce chemicals that can then be used in the manufacture of certain explosives and agricultural fungicides. Hydrazine also reacts with organic compounds to form alkyl hydrazines, used fuel in rocket and jet propulsion. Other reactions with organic compounds yield hydrazones and hydrazides, which are used in such pharmaceuticals as isoniazid (in the treatment of tuberculosis) and as chemical intermediates in the production of polymers and photographic chemicals.

ASSESSMENT:  He discovered hydrazine.

EXTRA CONNECTIONS: None

ONELINER: Theodore Curtius,  discoverer of hydrazine (spaceship fuel)

BIBLIOGRAPHY:

DSB

German Biographical  Dictionary