Electronic structure and solvent effect of 1H-benzimidazole-2-carboxylic acid monohydrate molecule

In this study, the spectroscopic properties of 1H-Benzimidazole-2-Carboxylic acid monohydrate molecule (C8H8N2O3 . H2O) were investigated by IR, Raman, UV-Vis spectroscopic techniques, theeoretically. The theoretical vibrational spectrum of 1H-Benzimidazole-2-Carboxylic acid monohydrate molecule calculations were performed by using GAUSSIAN 09 software. The molecular geometry and vibrational frequencies of 1H-Benzimidazole-2-Carboxylic acid monohydrate molecule were calculated using the density functional methods (B3LYP with 6-311G++(d,p) basis sets). In addition we investigated 9 different solvent effect on the vibrational frequencies of the related molecule. The molecular geometry and vibrational frequencies of 1H-Benzimidazole-2-Carboxylic acid monohydrate molecule were calculated gas phase B3LYP/6-311++G(d,p) level and in different solvents by B3LYP/6-311G++(d,p)/C-PCM method. The assignments on the fundamentals were proposed on the basis of total energy distribution (TED) calculations. The electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, were performed by time-dependent density functional theory (TD-DFT). Mulliken charge values, total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were, calculated and related results presented.