TORSION-ROTATION ENERGY-LEVELS, HINDERING POTENTIAL, AND INERTIAL PARAMETERS OF THE FIRST EXCITED VIBRATIONAL-STATE OF THE ANTISYMMETRIC O-H STRETCH IN HYDROGEN-PEROXIDE

Torsion-rotation energy levels of the excited vibrational state of the antisymmetric OH-stretch fundamental upsilon(5) of hydrogen peroxide are reported. These levels are determined from 1.24 m path difference Fourier transform spectra taken between 3200 and 4200 cm(-1) analyzed in conjunction with published ground vibrational state levels. The results include torsional states with n = 0, 1, 2. Many of the levels are perturbed. An analysis of these levels for J < 11, K < 7 with second-order perturbation theory based on a Hamiltonian used in earlier work to study the ground vibrational state yields molecular bond parameters and a hindering potential for the excited vibrational state. Perturbations preclude a definite determination of any cis splitting for n = 2. A fit of the experimental torsional levels with a one-dimensional torsional Hamiltonian gives a trans barrier height of 429 cm(-1) and a cis barrier height of about 2500 cm(-1). (C) 1995 Academic Press, Inc.