Theoretical Study on Infrared Spectrum of 4-Hydroxybenzhydrazide

Abstract

The geometry of 4-hydroxybenzhydrazide was optimized using DFT/B3LYP and MP2 with 6-311+G(d,p) basis set,the vibration frequency was calculated based on the stable structure at the same level,the normal modes were analyzed and the vibration frequencies were assigned.Compared with the experimental spectrum,it was found that the vibrational frequencies of hydroxyl,amino and C—H have significant differences between the experimental and the computational values.In order to explain the differences,a compound was obtained,in which a 4-hydroxybenzhydrazide molecule was substituted with ammonia molecule,to simulate the effect from neighbor molecules employing MP2.The results of calculation are in agreement with the experiment,which indicates that the interaction between molecules can not be ignored and MP2 is reliable on the investigating the vibration spectrum of the title compound.