AB-INITIO CALCULATIONS AND VIBRATIONAL SPECTROSCOPY ON THE PHENYLENEDIAMINE ISOMERS

Molecular orbital calculations at HF and MP2 levels have been performe d using the 6-31G* basis set for full geometry optimization of the ph enylenediamine isomers. Our results show that only a transoid conforme r is found for o-phenylenediamine, whereas cis and trans conformers ex ist for m-and p-phenylenediamine. Vibrational normal modes have been a lso analyzed for the gas phase and in chloroform solution, and compare d with experimental data we have obtained using FTIR spectroscopy. (C) 1998 Elsevier Science B.V.