Popov, Aleksandr Nikiforivich
POPOV, ALEKSANDR NIKIFORIVICH
(b. Vitebsk region [oblast], Russia, 1840 [?]; d. Warsaw, Russia [now Poland], 18 August 1881) chemistry.
Popov studied at Kazan University from 1861 to 1865, taught chemistry at that university until 1869, and then was professor of chemistry at Warsaw University. During the winter of 1871–1872 he worked in Kekulé’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.
Popov’s best-known achievement is his rule relating to ketones. The results of his work in this area 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 . G . 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.
Popov’s writings include “Ueber die Isomerie der Ketone,” in Zeitschrift für Chemie, n.s. 1 (1865), 577–580; and in Annalen der Chemie und Pharmacie, 145 (1868), 283–292; Ob okislenii ketonov odnoatomnykh(“On the Oxidation of Monoatomic Ketones”; Kazan, 1869); “Bestimmung der Constitution von Alkoholrdikalen durch Oxydation aromatischer Kohlenwasserstoffe,” in Berichte der Deutschen chemischen Gesellschaft, 5 (1872), 384–387, written with T. Zincke; “Die Oxydation der Ketone als Mittel zur Bestimmung der Constitution der Säuren und Alkohole,” in Annalen der Chemie und Pharmacie, 162 (1872), 151–160; O zakonnosti okislenia ketonov i o primenenii ee k opredeleniyu stroenia alkogoley i kislot (“On the Regularity of Oxidation of Ketones and Its Application to the Determination of the Structure of Alcohols and Acids”; Warsaw, 1872); and “Pisma k A.M. Butlerovu” (“Letters to A.M. Butlerov”), in Pisma russkikh khimikov k. A. M. Butlerovu. Nauchnoe nasledstvo (“Letters of Russian Chemists to A.M. Butlerov. Scientific Legacy”), IV (Moscow, 1961), 305–359, Popov’s last chemical works are in Sbornik rabot khimicheskoy laboratorii Varshavskogo universiteta (“Collection of Works of the Chemical Laboratory of Warsaw University” Warsaw, 1876).
A secondary source is G. V. Bykov, “Ocherk zhizni i deyatelnosti Aleksandra Nikiforovicha Popova” (“A Sketch of the Life and Work of . . . Popov”), in Trudy Instituta istorii estestvoznaniya i tekhniki . . ., 12 (1956), 200–241, with a bibliography of Popov’s writings on 241–245.
G. V. Bykov