DISSOCIATIVE ELECTRON-ATTACHMENT TO CONDENSED AND ADSORBED HALOMETHANES

Dissociative electron attachment (DEA) processes have been observed an d characterized for submonolayer and multilayer quantities of CCl4, CD Cl3, CD2Cl2, CH3Cl, and CH3Br adsorbed on metallic substrates and subm onolayer quantities adsorbed onto Kr spacer layers. Anion yields (Br-, Cl-, H-, D-) are reported for incident electron energies from 0 to 12 eV; no desorbing polyatomic anion fragments were detected. The result s are compared to the gas-phase DEA analogs and demonstrate the pertur bations on the DEA process that are introduced by the presence of the highly polarizable environment (molecular solid+ metal substrate). We also report the first observation of H-(D-) produced by DEA of halomet hanes containing hydrogen (deuterium).