Theoretical investigated of structure parameters and vibrational properties of 3,4-pyridinedicarboxylic acid molecule

In this study, the structural parameters and vibrational analysis of 3,4 Pyridinedicarboxylic acid molecule were investigated using experimental techniques(FT-IR, FT-Raman, NMR, and UV) and quantum chemical calculations. FT-IR and FT-Raman spectra of 3,4 Pyridinedicarboxylic acid in the solid phase were recorded in the region 4000-400 cm-1 and 4000-50 cm-1 respectively. The geometric parameters and energies were obtained for all different and possible conformers by using DFT/B3LYP method and 6-311++G(d,p) basis set . There are sixteen conformers C1-C16 for 3,4 Pyridinedicarboxylic acid molecule and the most stable conformer is the C1 conformer. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes calculated with SQM (scaled quantum mechanics)method.13C and 1H NMR spectra were recorded and chemical shifts were calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set. The UV absorption spectrum of studied molecule was recorded the range of 190?400 nm by using solvent ethanol. The optimized geometric parameters were compared with the X-ray results derived from complexes of this molecule.