Role of intersystem crossing in the dynamics of the O(3P)+ICl reaction

Reactive scattering of O(3P) atoms with ICl molecules has been studied at an initial translational energy E ∼ 98 kJ mol-1 using a supersonic beam of O atoms seeded in He buffer gas generated from a high temperature radiofrequency discharge source. A mildly peaked angular distribution of IO reactive scattering slightly favouring the forward direction is observed with a product translational energy distribution which peaks at a very low fraction f′ ∼ 0·04 of the total available energy with a long tail extending out to higher energy. This compares with a more sharply peaked angular distribution at lower initial translational energy E ∼ 45 kJ mol-1. In both cases, the product translational energy distributions are shifted to higher energy for the forward and backward scattering compared with sideways scattering. Extended phase space calculations indicate that reaction leading to IO reaction product is confined to very small impact parameters b m ∼ 1·2 A at high initial translational energy increasing to b m ∼...