H/D isotope effects on formation and photodissociation of HKrCl in solid Kr

Abstract

The HCl (DCl)/Kr matrixes were irradiated at 193 nm, which produced matrix-isolated H (D) and Cl atoms as permanent photolysis products. The annealing-induced formation of HKrCl and DKrCl was used as a measure of atomic hydrogen (H and D) mobility at various annealing temperatures (from 24 to 30 K). The temperature dependencies of the HKrCl and DKrCl formation rates yield ∼64 and 68 meV for the corresponding activation energies estimating the isotope effect on atomic hydrogen mobility in solid Kr (D slower than H). The difference in mobility of H and D atoms allowed us to demonstrate a reaction between D atoms and HKrCl molecules, and the suggested kinetic model is in good agreement with experiment. In addition, the H/D isotope effects on the solid-state photodissociation of HCl and HKrCl are studied and discussed.