Determination of the substituent constant σp- for the thioamide group -CSNH2 from the ionization of anilines and phenols

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Title:Determination of the substituent constant σp- for the thioamide group -CSNH2 from the ionization of anilines and phenols
Creators:
Polášek, Miroslav
Waisser, Karel
Bouček, Tomáš
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 56, 12, pp. 2964-2968

Abstract

Thermodynamic ionization constants p<i>K</i><sub>a</sub> 2.62 ± 0.01 for the primary aromatic amino group of 4-aminothiobenzamide and p<i>K</i><sub>a</sub> 8.28 ± 0.01 for the phenolic hydroxy group of 4-hydroxythiobenzamide have been determined by ultra-violet spectrophotometry at 25°C. By using these p<i>K</i><sub>a</sub> values and the Hammett equations (log <i>K</i><sub>a</sub> vs σ) for the ionization of fourteen 3- or 4-substituted phenols and thirteen 3- or 4-substituted anilines the substituent constant σ<sub>p</sub><sup>-</sup> = 0.68 (from the ionization of anilines) or σ<sub>p</sub><sup>-</sup> = 0.73 (from the ionization of phenols) of the thioamide group -CSNH<sub>2</sub> was calculated.

Title:Determination of the substituent constant σp- for the thioamide group -CSNH2 from the ionization of anilines and phenols
Creators:
Polášek, Miroslav
Waisser, Karel
Bouček, Tomáš
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:56
Number:12
Page Range:pp. 2964-2968
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19912964UNSPECIFIED
ID Code:5201
Item Type:Article
Deposited On:22 Feb 2010 11:32
Last Modified:22 Feb 2010 10:33

Citation

Polášek, Miroslav; Waisser, Karel; Bouček, Tomáš (1991) Determination of the substituent constant σp- for the thioamide group -CSNH2 from the ionization of anilines and phenols. Collection of Czechoslovak Chemical Communications, 56 (12). pp. 2964-2968. ISSN 0010-0765

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