Substituent effect on IR, 1H and 13C NMR spectral data in n-(substituted phenyl)-2-cyanoacetamides: A correlation study

Chemical Industry and Chemical Engineering Quarterly

关键词: N-(substituted phenyl)-2-cyanoacetamides;    LFER analysis;    IR and NMR spectra;    SCS shift;    Hammett equation;   

DOI  :  10.2298/CICEQ120109044M

来源: DOAJ

【 摘 要 】

Linear free energy relationships (LFER) were applied to the IR, 1H and 13CNMR spectral data of N-(substituted phenyl)-2-cyanoacetamides. A variety ofsubstituents were employed for phenyl substitution and fairly goodcorrelations were obtained using the simple Hammett and the Hammett-Taftdual substituent parameter equations. The correlation results of thesubstituent induced 13C NMR chemical shifts (SCS) of the C1, C=O and N-Hatom indicated different sensitivity with respect to electronic substituenteffects. A better correlation of the SCSC=O with a combination ofelectrophilic and nucleophilic substituent constants indicated a significantcontribution of extended resonance interaction (π-delocalization) within theπ1-unit. The conformations of the investigated compounds were studied usingthe DFT B3LYP/6-311G method and, together with the results of 13C NMR andIR spectroscopic studies, a better insight into the influence of such astructure on the transmission of electronic substituent effects wasobtained.

【 授权许可】

Unknown