State-specific dissociation enhancement of ionic and excited neutral photofragments of gaseous CCl4 and solid-state analogs following Cl 2p core-level excitation.

The state-selective dissociation pathways for ionic and excited neutral fragments of gaseous and condensed CCl4 following Cl 2p core-level excitation have been characterized by combining photon-induced ionic dissociation, x-ray absorption, resonant photoemission and UV/visible dispersed fluorescence measurements. The Cl 2p→7a*1 excitation of CCl4 induces significant enhancement of the Cl+ desorption yield in the condensed phase and the CCl+ yields in the gaseous phase. Based on the resonant photoemission studies, excitations of Cl 2p electrons to valence orbitals and Rydberg states decay predominantly via the spectator Auger transitions. The transitions of Cl 2p electrons to the Rydberg state of gaseous CCl4 lead to a noteworthy production of excited atomic neutral fragments (C*) and excited diatomic neutral fragments (CCl*). These results provide insight into the state-selective ionic and neutral fragmentation processes of molecules via core-level excitation. [ABSTRACT FROM AUTHOR]