Laboratory of Environment Spectroscopy, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 1125, Hefei 230031, People's Republic of China
Abstract:
Acetic acid (CH3COOH) and pyridine (C5H5N) 1:1 complex was subjected to Density Functional Theory (DFT) calculations using 6-311G(d,p) basis set. Five equilibrium isomers were located, and the most stable structure has a strong NH–O hydrogen-bonding interaction. A normal-mode analysis of the vibrations of the five isomers was carried out and compared with the experimental values. The calculations indicate that solvents enhance significantly the strength of hydrogen bond as shown by the decrease of the N–H distance and appreciable red shift of the H–O vibration mode and blue shift of NH–O vibration mode.