Vibrational Spectroscopic and Computational Studies on Bis(2-aminopyridinium)fumarate - Fumaric Acid (1:1) Complex

The new vibrational and computational studies on bis(2-aminopiridinium) fumarate - fumaric acid (1:1) complex have been made. The molecular geometry, vibrational frequencies and intensities of vibrational bands have been interpreted with the aid of structure optimization based on density functional theory (B3LYP) method with 6-311++G(d,p) basis set. The highly occupied-lowly unoccupied molecular orbital energies and chemical reactivity of the molecule have been calculated with time-dependent density functional theory approach. Stability energies of the molecule have been studied using natural bond orbital analysis. The predicted nonlinear optical properties of the title compound are much greater that those of urea. In addition, the molecular electrostatic potential surfaces and thermodynamic properties were calculated.