期刊名称:Chemical Industry and Chemical Engineering Quarterly
印刷版ISSN:1451-9372
出版年度:2013
卷号:19
期号:1
页码:67-78
DOI:10.2298/CICEQ120109044M
出版社:Association of the Chemical Engineers
摘要:Linear free energy relationships (LFER) were applied to the IR, 1H and 13C NMR spectral data of N-(substituted phenyl)-2-cyanoacetamides. A variety of substituents were employed for phenyl substitution and fairly good correlations were obtained using the simple Hammett and the Hammett-Taft dual substituent parameter equations. The correlation results of the substituent induced 13C NMR chemical shifts (SCS) of the C1, C=O and N-H atom indicated different sensitivity with respect to electronic substituent effects. A better correlation of the SCSC=O with a combination of electrophilic and nucleophilic substituent constants indicated a significant contribution of extended resonance interaction (π-delocalization) within the π1-unit. The conformations of the investigated compounds were studied using the DFT B3LYP/6-311G method and, together with the results of 13C NMR and IR spectroscopic studies, a better insight into the influence of such a structure on the transmission of electronic substituent effects was obtained.
关键词:N-(substituted phenyl)-2-cyanoacetamides; LFER analysis; IR and NMR spectra; SCS shift; Hammett equation