FIRST ORDER HYPERPOLARIZABILITY, HOMO-LUMO AND VIBRATIONAL ANALYSIS OF LISOLEUCINE, L-ISOLEUCINE MALEATE (LIM) AND L-ISOLEUCINE OXALATE (LIO) BY DFT METHODS

Abstract

In this work, the molecular structure, harmonic vibrational frequencies of L- isoleucine (LI), L-isoleucine Maleate (LIM) and L-isoleucine Oxalate (LIO) have been investigated. The optimized molecular geometries, first order hyperpolarizabilities and vibrational frequencies have been calculated using B3LYP/6-31G. The HOMO and LUMO energy calculation reveals that the charge transfer exist within the molecules. The Fourier Transform Infrared (FT-IR) of LIM and LIO are recorded in the regions 4000-400 cm-1. The observed and calculated wave numbers are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed spectra.