EXAMINATION OF THE BR+HL, CL+HL, AND F+HL HYDROGEN ABSTRACTION REACTIONS BY PHOTOELECTRON-SPECTROSCOPY OF BRHL-, CLHL-, AND FHL-

The photoelectron spectra of the ions BrHI-, ClHI-, and FHI-, along with their deuterated counterparts, are presented. These spectra provide information on the transition state region of the potential energy surfaces describing the exothermic neutral reactions X + HI→HX + I(X = Br, Cl, F). Vibrational structure is observed in the BrHI- and ClHI- spectra that corresponds to hydrogen atom motion in the dissociating neutral complex. Transitions to electronically excited potential energy surfaces that correlate to HX + I(2P 3/2,2P1/2) products are also observed. A one-dimensional analysis is used to understand the appearance of each spectrum. The BrHI- spectrum is compared to a two-dimensional simulation performed using time-dependent wave packet propagation on a model Br + HI potential energy surface. © 1990 American Institute of Physics.