Vibrational Assignment and Structure of Some Derivatives of Chloro-Salysilideneanilin

The purpose of the current study is to investigation the structural and intramolecularhydrogen bonding (IHB) strength of some derivatives of chloro-salysilideneanilin (n-Cl-SaAn)using DFT calculations. The geometries of the ortho-, meta-, and para- of n-Cl-SaAn, which theposition of Cl is considered respect to C-C=N group (o-Cl-SaAn, m-Cl-SaAn and p-Cl-SaAn),are fully optimized by density functional theory (DFT) calculation. The molecular structures andvibrational frequencies are calculated at B3LYP/6-311++G**. The geometrical parameters andthe vibrational frequencies related to intramolecular hydrogen bonding of these compounds arecompared in Table 1. The results are shown the N···H distance and then the O-H bond length ino-Cl-SaAn respectively are shorter and longer than other derivatives. Also, the νOH and νOD ino-Cl-SaAn in comparison with the corresponding values are shorter than other derivatives. Bycomparing theoretical result, the trend of strength of hydrogen bond of the above mentionedcompounds is as follows: o-Cl-SaAn > m-Cl-SaAn > p-Cl-SaAn.

Keywords:

DFT , IHB , SaAn , Vibrational Frequencies