ENERGY AND ANGULAR-MOMENTUM DISPOSALS IN THE VIBRATIONALLY MEDIATED PHOTODISSOCIATION OF HOOH AND HOOD - INTRAMOLECULAR PROPERTIES VIA PHOTOFRAGMENT MAPPING

Vector correlations, vibrational fragment pair correlations and population distributions in OH(D) photofragments generated via two photon, vibrationally mediated photodissociation of HOOH(D) at selected wavelengths near 750 nm, have been determined using polarized, Doppler-resolved LIF spectroscopy. These measurements, together with a knowledge of the direct, single photon dissociation dynamics at comparable supplied energies, allow assignment of the two electronic transitions (A1A and B1B← X1A) contributing to the continuum accessed in the double resonance experiments, establish the minor influence of rotational torques exerted on the elec- tronically excited potential energy surfaces, when these are accessed at large 0-0 bond extensions, establish strong photofragment rotational excitation as originating pri- marily from the molecular ro-vibrational motion in the intermediate high overtone state, allow the use of an approximate classical treatment to estimate the average energy disposed into each vibrational mode in the vibrationally excited HOOH(D) molecules ‘interrogated’ by secondary photon absorption at -750nm. The ‘interrogated’ molecules, initially excited via the 4vO-H ‘local mode’ transition are found to possess significant OOH(D) bending and HO-OH(D) torsional character in addition to contributions from HO-OH(D), H-O, and D-O Stretching. The intramolecular vibrational mode composition together with the component of parent molecular rotation about the a-axis, is effectively mapped into the final photofragment quantum state distributions. © 1990 Taylor & Francis Group, LLC.