Substituent Effects on Conformational Equilibria: Substituted Thiobenzanilides

[img]PDF - Authorized users only
Language: English
92Kb
Title:Substituent Effects on Conformational Equilibria: Substituted Thiobenzanilides
Creators:
Waisser, Karel
Palát, Karel
Exner, Otto
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 64, 8, pp. 1295-1306
Uncontrolled Keywords:Infrared spectroscopy, Thioamides, Thiobenzanilides, Transmission effects, Conformation equilibrium, Substituent effects, Hammett equation

Abstract

Infrared absorption spectra of 38 thiobenzanilides in tetrachloromethane solutions were recorded in the ν(N-H) region. From the integrated absorption intensity of the computer-resolved N-H bands, the abundance of the <i>Z</i> and <i>E</i> conformations was calculated. The values of pertinent log <i>K</i><sub>C</sub> depend on substitution in an unexpected way which cannot be described by the Hammett equation or by any other known type of modified constants σ. The only regularity observed is that the substituent effects from the two benzene rings of thioanilide are additive with a remarkable precision. The ν(N-H) frequencies are not much sensitive to substitution and the dependence is not simple: only ν(N-H) of the <i>E</i> conformer depend on substitution in a regular way. <p>

Title:Substituent Effects on Conformational Equilibria: Substituted Thiobenzanilides
Creators:
Waisser, Karel
Palát, Karel
Exner, Otto
Uncontrolled Keywords:Infrared spectroscopy, Thioamides, Thiobenzanilides, Transmission effects, Conformation equilibrium, Substituent effects, Hammett equation
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:64
Number:8
Page Range:pp. 1295-1306
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19991295UNSPECIFIED
ID Code:1556
Item Type:Article
Deposited On:06 Feb 2009 17:10
Last Modified:06 Feb 2009 16:10

Citation

Waisser, Karel; Palát, Karel; Exner, Otto (1999) Substituent Effects on Conformational Equilibria: Substituted Thiobenzanilides. Collection of Czechoslovak Chemical Communications, 64 (8). pp. 1295-1306. ISSN 0010-0765

Repository Staff Only: item control page