Internal Energy of Reaction Products by Velocity Analysis. II. Scattered KBr* from the Crossed Molecular Beam Reaction K+Br2

The velocity distribution of excited KBr* formed in reactive collision between crossed beams of velocity-selected K and thermal Br2 has been measured at several laboratory scattering angles and initial relative kinetic energies of 1.26, 2.14, and 3.27 kcal/mole. From these observations qualitative information may be inferred regarding the internal energy distribution function and the angular distribution of reactive scattering in the center-of-mass (c.m.) system. It is found that (1) the KBr* internal energy distribution is broad, extending over a range of at least 30 kcal/mole, with most of the 46 kcal/mole exothermicity of the reaction appearing in the form of internal excitation of KBr*, and (2) the angular distribution of reactive scattering in the ``forward'' direction (KBr preferring the direction of the incident K in the c.m. system), is characterized by a cone in the c.m. with an angle of generation of at least 30°.