The application of the Hammett equation to ¹³C N.M.R. spectrometry. V. The transmission of electronic effects through azophenylene and ethenylphenylene groups

Abstract

The ¹³C n.m.r. spectra of a number of ethyl (3-aryl)azo-, (4-aryl)azo-, 2-(4-arylethenyl)-cinnamates have been measured in CDCl₃. Comparison of the data with those for the corresponding ethyl 3-arylpropenoates has been used to investigate the attenuation of electronic effects by the 3- and 4-azophenylene and the 4-ethenylphenylene linkages.