Structural, vibrational, NLO, MEP, NBO analysis and DFT calculation of bis 2,5-dimethylanilinium sulfate

A new organic–inorganic salt, bis 2,5-dimethylanilinium sulfate has been synthesized by slow evaporation method at room temperature and characterized by single X-ray diffraction, FT-IR and FT-Raman spectroscopies. The optimized molecular structure, vibrational wavenumbers, atomic charges, molecular electrostatic potential, NBO, NLO and electronic properties were calculated by the density functional theory (DFT) method using the B3LYP function with the 6-31G(d,p) basis set. The complete assignments of the vibrational spectra were carried out with the aid of potential energy distribution (PED). Simulation of infrared and Raman spectra led to excellent overall agreement with the observed spectral patterns. The stability and charge delocalization of the molecule were studied by natural bond orbital (NBO) analysis. In addition, a molecular electrostatic potential map (MEP) of the title compound has been analyzed for predicting the reactive sites. NLO properties and Mulliken charges were also calculated and interpreted. The lowering in the HOMO and LUMO energy gap explains the eventual charge transfer interactions that take place within the molecules.