Collect. Czech. Chem. Commun. 1986, 51, 2656-2664

Force field for out-of-plane vibrations of pyrazine

Juan F. Arenas, Juan I. Marcos, Juan T. Lopez-Navarrete and Juan C. Otero

Department of Physical Chemistry, Faculty of Sciences, 29071 - Malaga, Spain


A general quadratic force field has been calculated for the out-of-plane vibrations of pyrazine by the MINDO/3 method. The first derivatives of the energy were computed analytically and the second derivatives of energy numerically. The force constants so obtained have been refined to fit the observed frequencies of -h4, -d4 and cis-pyrazine-d2. The calculations proved our assignment suggested previously, though the disagreement between theory and experiment for the Au vibrations of pyrazine needs additional experimental and theoretical data for clarification.