A new look into conformational, vibrational and electronic structure analysis of 3,4-dimethoxybenzonitrile

The most stable geometry of 3,4-dimethoxybenzonitrile has been determined by potential energy surface scan with the dihedral angle C4C5O9C11 by B3LYP/6-311++G(d,p) method. The FTIR and FT-Raman spectra of 3,4-dimethoxybenzonitrile have been analysed Quantum chemical studies were performed with B3LYP method using 6-311++G(d,p), 6-31G(d,p) and cc-pVTZ basis sets. The effect electron donating OCH3 and electron withdrawing CN groups on the ring parameters were thoroughly analysed. The structural parameters, energies, thermodynamic parameters, vibrational frequencies and the NBO charges were determined. The 1H and 13C isotropic chemical shifts (δ ppm) with respect to TMS were also calculated using the gauge independent atomic orbital method. The delocalisation energy of the different types of bonding interactions was investigated.