ZERO ELECTRON KINETIC-ENERGY SPECTROSCOPY OF THE KRBR-, XEBR-, AND KRCL- ANIONS

Three rare-gas halide (RgX(-)) anions, KrBr-, XeBr-, and KrCl-, and th e corresponding neutral, open-shell van der Waals complexes are studie d with anion zero electron kinetic energy spectroscopy. The spectra fo r each system reveal well-resolved progressions in the low frequency v ibrations of the anion and one or more of the three neutral electronic states accessed by photodetachment, providing a detailed spectroscopi c probe of the Rg-X- and Rg-X interaction potentials. In the case of K rBr-, transitions to all three of the ''covalent'' neutral electronic states (the X1/2, I3/2, and II1/2 states) were observed. For XeBr-, tr ansitions to the X1/2 and II1/2 neutral states were observed. For KrCl -, only the X1/2 state could be studied. From our data, we construct m odel potentials for the anion and each observed neutral state, and the se are compared with other experimental and theoretical potentials. (C ) 1998 American Institute of Physics. [S0021-9606(98)01037-X].