15min:

DAVID RUEDA, O. V. BOYARKIN AND T. R. RIZZO, INSTITUT DE CHIMIE PHYSIQUE MOLECULAIRE, EPFL, CH - 1015 LAUSANNE; ANDREI CHIROKOLAVA, INDRANATH MUKHOPADHYAY AND DAVID S. PERRY, DEPARTMENT OF CHEMISTRY, UNIVERSITY OF AKRON, AKRON, OHIO 44325.

The spectrum of the first overtone OH stretch band (2 ₁) in jet-cooled methanol has been measured using Infrared Laser Assisted Photofragment Spectroscopy (IRLAPS) and detailed assignments have been made. In addition to the torsional fundamental band ( v_t=0) it was possible to observe and assign the torsional combination band with ( v_t=1 and 2). These transitions are very week but can be clearly resolved in the spectra. In total, 131 transitions reaching 19 different K levels in the 2 ₁ state have been fit to a global torsion-rotation Hamiltonian and the leading torsion-rotation parameters have been determined. Assignments for the much weaker and irregular torsional band structure for 3 ₁+ ₁₂ and 3 ₁+2 ₁₂ are in progress.