Density Functional Theory Study on Conformers of Benzoylcholine Chloride

The optimized molecular structures and vibrational frequencies and also gauge including atomic orbital (GIAO) 1H and 13C\udNMR shift values of benzoylcholine chloride [(2-benzoyloxyethyl) trimethyl ammonium chloride] have been calculated using\uddensity functional theory (B3LYP) method with 6-31++G(d) basis set. The comparison of the experimental and calculated infrared\ud(IR), Raman, and nuclear magnetic resonance (NMR) spectra has indicated that the experimental spectra are formed from\udthe superposition of the spectra of two lowest energy conformers of the compound. So, it was concluded that the compound\udsimultaneously exists in two optimized conformers in the ground state. Also the natural bond orbital (NBO) analysis has supported\udthe simultaneous exiting of two conformers in the ground state. The calculated optimized geometric parameters (bond lengths and\udbond angles) and vibrational frequencies for both the lowest energy conformers were seen to be in a well agreement with the\udcorresponding experimental data