The spectroscopic NMR analysis of 2-dicyanovinyl-5-phenylthiophene by the density functional method

Abstract

Quantum chemistry calculations have been performed by using the Gaussian03 program to compute the optimized geometry and harmonic vibrational frequency of 2-dicyanovinyl-5-phenylthiophene (C14H8N2S) in the ground state. Atomic charges at B3LYP/6-311++G(d,p) level are also calculated. Potential energy distributions (PEDs) using MOLVIB program are also used to interpret the theoretical vibrational spectra of the title compound. A detailed interpretation of the infrared spectra of the title compound is reported. The theoretical spectrograms for the IR spectra of the title compound have been constructed. The crystal structure obtained by molecular mechanics belongs to the P21 space group, with lattice parameters Z = 2, a = 6.6745 Å, b = 14.7672 Å, c = 11.0986 Å, ρ = 0.921 g cm–3. In addition, the 13C and 1H NMR are further investigated by the B3LYP/6-311++G(d,p) and B3LYP/6-311++G(2d,2p) methods.