Evidence for the onset of three-body decay in photodissociation of vibrationally excited CHFCl 2Picosecond real time study of the bimolecular reaction O ( 3 P)+ C 2 H 4 and the unimolecular photodissociation of CH 3 CHO and H 2 CO Polarized 1ϩ1Ј REMPI combined with TOFMS detection was used to obtain recoil speed distributions, NO product rotational distributions, andv-j NO angular correlations in the photofragmentation of CF 3 NO between 585 and 650 nm. At wavelengths longer than 610 nm dissociation occurs only on the S 0 potential energy surface of CF 3 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 vЌj NO angular correlation, reaching a maximal value of ␤ 0 0 (22)ϭϪ0.308Ϯ0.052. 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.