			10min:

VIBRATIONAL OVERTONE EXCITATION OF METHYL HYDROPEROXIDE AND HYDROXYL RADICAL FORMATION.

LAURA M. HAYNES, KRISTEN M. VOGELHUBER AND SHIZUKA HSIEH, Chemistry Department, Smith College, Northampton, MA 01063.

Laser photoacoustic spectra of methyl hydroperoxide in the regions of exciting four and five quanta of O-H stretch show features due to excitation of torsional motion about the O-O bond in addition to O-H stretch. Detection of OH radicals by laser-induced fluorescence confirms that states near five quanta of O-H stretch dissociate along the O-O bond. Photoacoustic and action spectra are compared with simulations from a simple model that assumes adiabatic separation of torsion and O-H stretch and that takes into account the dipole moment dependence on dihedral angle.