Interaction Potentials Involving Br Atoms

Abstract

Three-body Br-atom recombination rate constants, obtained recently over a relatively wide temperature range, were used to estimate the interaction potentials between recombining atoms and an inert third body, M. It was found that the most reasonable set of assumptions yields εLJNe = 0.6 kcal/mol, εLJAr = 1.4 cal/mol, εLJKr = 2.0 kcal/mol, and εLJN2 = 1.5 kcal/mol, where εLJM is the depth of the interaction potential between Br and M. These values of εLJM are several times larger than εLJM between M and Kr, which is bromine's nearest neighbor in the periodic table. The calculations show that use of a more realistic (Sutherland, rather than hard-sphere) potential between the recombining Br and BrM complex reduces, in some cases by as much as 50%, the value of εLJM. The corresponding three-body reaction probabilities, P's, vary from, roughly, 0.01 to unity, depending upon the details of the assumed recombination mechanism, and the nature of the third body. For M as an inert gas, P decreases with the increasing of molecular weight.