REACTIONS OF OXYGEN-ATOMS WITH VAN-DER-WAALS COMPLEXES - THE EFFECT OF COMPLEX-FORMATION ON THE INTERNAL ENERGY-DISTRIBUTION IN THE PRODUCTS

Reactions of atomic oxygen with complexes containing HCl are investiga ted and the OH product state distributions are compared to those obser ved for the corresponding reactions of HCl monomers. In previous studi es of reactions of O(P-3) with HCl and hydrocarbon complexes, rotation ally colder OH product state distributions were observed, when compare d to the corresponding reactions of monomers. In contrast, we find tha t reactions of O(D-1) with HCl clusters yield OH rotational distributi ons that are unaffected by the incorporation of HCl into a van der Waa ls complex. Quasiclassical trajectories are run on collisions of oxyge n with HCl and Ar ... HCl at 1 eV collision energies to investigate th e differences in the dynamics of the O(D-1) and O(P-3) reactions. It i s found that when the van der Waals complex is longer lived than the c ollision complex, rotational and vibrational cooling are observed. In contrast, when the dissociation of the van der Waals complex is prompt ; compared to the collision complex lifetime, the effects of complex f ormation on the internal energy of the OH product become negligible. ( C) 1998 American Institute of Physics.