Abstract

COMPUTATIONAL STUDY ON THE ELECTRONIC STRUCTURE OF PHENETHICILLIN ZWITTERIONS BY AUSTIN MODEL-1 (AM1) METHOD

Bojja Rajeshwar Rao* and Dasari Chandrasekhar Rao

Abstract

The geometry, conformation and electronic structure of phenethicillin zwitterions have been optimized and calculated by using semiempirical molecular orbital method (AM1), which includes experimental parameters and extensive simplification of the Schrodinger’s equation (HΨ=EΨ) for calculation of various properties in the gas phase. The mechanism of formation of zwitterions has been studied by comparison of the different net charges on nitrogen atoms in the molecule. In this connection, the heats of formation (ΔHf o), dipole moment (μ), ionization potential (IP), full atomic charges and energies of frontier molecular orbitals (EHOMO and ELUMO) have been performed and discussed. The conformational changes and electronic properties have also been discussed for stable conformations.

Keywords: Phenethicillin, zwitterions, HOMO, LUMO, frontier molecular orbitals.