Vibration al Freque ncies of ha lo-derivatives of an iline: A D FT Study

Anilin e and its derivatives ha ve been subj ected to many different types of scientific studi es up to know [۱–۲]. They have been widely used in a variety of industrial and commercial purposes, includin g dyestuff, pesticide and pharmaceuticals manu facturing. S ome of the para-substituted derivatives of anilines are loca l anesthetics and the am ino group i n these mole cules plays an importa nt role in th e interaction with the receptor. T he inclusion of a substituent group in aniline l eads to the v ariation of charge distri bution in the molecule and consequ ently this greatly affects the structural, electronic and vibration para meters. Molecular geometry changes due to enhanced interaction betw een the aromatic ring and the amino group [۳]. This paper is a continu ation of ou r earlier work related to the study o f ab initio for predictin g the experimental parameters [۵-۶].In this work a theoret ical study o f vibrationa l frequenci es for fluoro aniline, chloro aniline, bromo aniline derivatives at substituted of o rto, meta, para , {(۲,۳), (۲,۴), (۲,۵), (۲,۶), (۳,۴ ) , (۳, ۵)} di halo aniline and {(۲,۳,۴), (۲,۳,۵) ,(۲,۴,۵)}tri halo anilin e , {(۲,۳,۴,۵ ) , (۲,۳ ,۴,۶) , (۲,۳,۵,۶)} tetra halo a niline and {(۲,۳,۴,۵,۶)} panta halo aniline have been done at B۳LYP employing the ۶-۳۱G(d), ۶-۳۱G(d, p), ۶-۳۱++G(d, p), and ۶- ۳۱۱++ G(d,p) bas is sets. The optimized structural p arameters were used for calculation of vibrational frequencies.

کلیدواژه ها:

DFT ، aniline derivatives ، IR ، Vibrational frequencies