Thermodynamic functions and IR modes Calculation for newly Azo compounds by Using DFT Model

Abstract

Depended on (Gaussian 03) program for using Density Function Theory calculations (DFT/B3LYP) have been done after complete optimization of geometry on the newly azo (A, B) molecules . The geometric parameter (bond lengths and bond angles) , charge , thermodynamic data and the fundamental vibration frequencies (3N-6) along with their assignments and the corresponding IR absorption intensities for each one of the two molecules where , also, The MOPAC Computational Packages (semi-empirical method , PM3 model) employed through out this study to compute the heats of formations, dipole moments, orbital energies (HOMO, LUMO) and ionization energies . The compound –B is more stability because it has less heats of formation and entropy , and easier ionization than compound-A , the shown results that each one nitrogen atom of compound-B highest electron densities than compound-A . The higher frequencies values for the (O-H) stretch fundamental vibration mode.