Aleksandr Nikiforivich Popov

Background

Aleksandr Nikiforivich Popov was born around 1840 in the Vitebsk region, Russian Empire (present-day Belarus).

Education

Popov studied at Kazan University from 1861 to 1865.

Career

Popov taught chemistry Kazan University until 1869, and then was a professor of chemistry at Warsaw University. During the winter of 1871-1872, he worked in Kekule’s laboratory at Bonn.

Popov’s first publication, which appeared while he was working in Butlerov’s laboratory at Kazan (1865), was devoted to refuting Kolbe’s views on the isomers of ketones and to proving the identity of the “units of affinity” (valencies) of the atom of carbon. His basic contribution lies, however, in the development of destructive oxidation, in which a “choromium mixture” (K2CrO7 — H2SO4) is used as an oxidizing agent for the study of the chemical structure of organic compounds.

The results of his work in the area of ketones were generalized in his master’s thesis (1869). He found that in the oxidation of ketones the radicals form the following order in their affinity for the former carbonyl group: C6H5 and R3C > CH3 > RCH2 > R2CH > C6H5CH2(R = alkyl) - and that in the oxidization of ketones the carbonyl group remains joined to the most stable radical.

Gert G. Wagner made Popov’s rule more precise by showing that it deals with the main direction of the reaction. Popov’s rule was used by himself and other chemists to determine the structures of acids, alcohols, and metallo-organic compounds used for the synthesis of ketones.

Popov also pointed out the possibility of using “chromium mixture” to determine the structures of organic acids and alcohols. In the oxidation of alcohols he suggested >C = (OH)2 as an intermediate state.

Popov and Theodor Zincke showed that in the oxidization of alkylbenzenes, the splitting occurs so as to form the C6H5CH2 and the alkyl radicals, which are further oxidized independently. This method permitted the determination of the structure of lateral chains and consequently of compounds used for the synthesis of alkylbenzenes.

Popov’s letters to Butlerov show that Popov suggested to Kekule an important rule concerning the splitting of olefins during oxidization according to the site of the double bond. Kekulé first stated it in print, so that it is frequently called Kekulé’s rule.

Achievements

• Popov’s best-known achievement is his rule relating to ketones. He found that in the oxidation of ketones the radicals form the following order in their affinity for the former carbonyl group and that in the oxidization of ketones the carbonyl group remains joined to the most stable radical. Popov’s rule was used by himself and other chemists to determine the structures of acids, alcohols, and metallo-organic compounds used for the synthesis of ketones.
  
  Popov also pointed out the possibility of using “chromium mixture” to determine the structures of organic acids and alcohols.
  
  

Works

More photos

• book

  • Annalen Der Chemie Und Pharmacie

    (Volumes 161-162)

    1872
  • Annalen Der Chemie Und Pharmacie

    (Vol. 145)

    1868

Connections

collaborator:

Ernst Carl Theodor Zincke

1843 – 1928, Popov and Theodor Zincke showed that in the oxidization of alkylbenzenes, the splitting occurs so as to form the C6H5CH2 and the alkyl radicals, which are further oxidized independently.

associate:

Alexander Butlerov

References

• Dictionary of Scientific Biography
  1975