Dissociative Electron Attachment to CCl4, CHCl3, CH2Cl2 and CH3Cl

Resonance dissociative attachment of monoenergetic electrons in the energy range from 0.0 eV to 10 eV to CCl4, CHCl3, CH2Cl2 and CH3Cl has been studied using a trochoidal electron monochromator and a quadrupole mass filter. The following fragment negative ions as a function of electron impact energy could be observed: Cl−, Cl2−, CCl2− and CCl3− from CCl4; Cl−, HCl2 and CCl2− from CHCl3; Cl−, Cl2− and CCl2− from CH2Cl2 and Cl− and CH2Cl− from CH3Cl. — The attachment cross section decreases rapidly as H replaces Cl. Appearance potentials for the negative fragments and for CCl3 and CCl2 electron affinities in the limit of the excess energy are given.