Calculation of vibrational spectroscopic and NMR parameters of 2-Dicyanovinyl-5-(4-N,N-dimethylaminophenyl) thiophene by ab initio HF and density functional methods

Quantum chemistry calculations have been performed to compute optimized geometry, Mulliken charges, harmonic vibrational frequency at HF/6-311++G(d,p) and B3LYP/6-311++G(d,p) levels for 2-Dicyanovinyl-5-(4-N,N-dimethylaminophenyl) thiophene (C16H13N3S) in the ground state. Theoretical vibrational spectra of the title compound were interpreted by means of potential energies distributions (PEDs) using MOLVIB program. The research shows that the presence of intramolecular interaction in the title compound. The scaled harmonic vibrational frequencies have been compared with experimental vibrational frequencies. A detailed interpretation of the infrared spectra of the title compound is reported. The theoretical spectrograms for FT-IR spectra of the title compound have been constructed. In addition, the 13C and 1H NMR are calculated by B3LYP/6-311++G(d,p) and B3LYP/6-311++G(2d,2p) methods.