Photofragmentation studies of normal and deuterated trichloroethylene and tetrachloroethylene using synchrotron radiation

BAVA YANINA BELÉN; BERRUETA MARTINEZ YANINA; CAVASSO FILHO R. L.; DELLA VÉDOVA CARLOS O.; ROMANO ROSANA M.

Juiz de Fora

Mesa redonda; II Seminário de Físico Química na América Latina (FQAL2016); 2016

Universidade Federal de Juiz de Fora

In this work, and as part of a general project aimed to the elucidation of the photofragmentation mechanisms using synchrotron radiation of compounds relevant for atmospheric chemistry (see for example reference 1 and references cited therein) we present the study of trichloroethylene (HClC=CCl2, 3CE), deuterotrichloroethylene (DClC=CCl2, D3CE) and tetrachloroethylene (Cl2C=CCl2, 4CE) using synchrotron radiation between 10 and 1000 eV. The photoexcitation, photoionization and photofragmentation of the chlorinated compounds were studied in the TGM and SGM beamlines at LNLS, Campinas, Brazil, using the experimental station for gaseous samples and coincidence techniques. Photoelectron-Photoion-Coincidence (PEPICO) and Photoelectron-Photoion-Photoion-Coincidence (PEPIPICO) spectra were interpreted in terms of fragmentation mechanisms of M+ (in the electronic valence energy region) and M2+ (in the inner- and core-shell regions), respectively.Different fragmentation mechanisms were detected from the double charged molecular ion, giving Cl+/C2Cl2+/Cl and CCl2+/CCl2+ for 4CE, and Cl+/XC2Cl2+ and XC2Cl+/Cl2+ (with X = H or D) for 3CE and D3CE. Selected coincidence islands are depicted in Figure 1, for spectra taken at 287 eV, that corresponds to the excitation of the C 1s electrons. It is interesting to note that the XC2Cl+/Cl2+ fragments were produced after an atomic rearrangement processes.