Scalar and angular correlations in CF3NO photodissociation:: Statistical and nonstatistical channels

Polarized 1+1' REMPI combined with TOFMS detection was used to obtain recoil speed distributions, NO product rotational distributions, and mu-v-j(NO) angular correlations in the photofragmentation of CF3NO between 585 and 650 nm. At wavelengths longer than 610 nm dissociation occurs only on the S-0 potential energy surface of CF3 NO. At 585 nm the product recoil speed distribution is bimodal, with the higher speed component attributed to dissociation across a potential barrier on the T-1 surface. Measurements of the T-1 channel NO product trajectory show it has no laboratory frame rotational alignment or recoil anisotropy, but has a significant preference for v perpendicular to j(NO) angular correlation, reaching a maximal value of beta(0)(0)(22) =-0.308+/-0.052. The results are interpreted using the results of statistical phase space theory and classical trajectory calculations. It is concluded that S-0 channel dissociation occurs by a statistical dissociation mechanism whereas the T-1 channel dynamics is dominated by exit channel recoil forces due to a potential barrier. (C) 1999 American Institute of Physics. [S0021-9606(99)00719-9].