Photoionization and photofragmentation study of ClC(O)OSO2CF3 in the valence-, inner-, and core-electrons energy regions

MORENO BENTANCOURT, ANGÉLICA; YANINA BAVA; BERRUETA MARTINEZ, YANINA; CAVASSO FILHO, REINALDO L.; DELLA VÉDOVA, CARLOS OMAR; ERBEN, MAURICIO F.; GERONÉS, MARIANA; ROMANO, ROSANA M.

Campinas

Workshop; 23ª Reunião Anual de Usuários (RAU) Laboratório Nacional de Luz Síncrotron; 2013

LNLS

As part of a research project dedicated to the study of the electronic properties ofmolecules containing the SO2- group and halogen atoms, we present here the fragmentationstudies following phoionization of valence, inner-shell and core-shell electronsof chlorocarbonyl trifluoromethanesulfonate, ClC(O)OSO2CF3. This compoundhas been prepared by our research group, and its conformational, structuraland spectroscopic properties were studied using different experimental and theoreticaltechniques. Gas electron diffraction and vibrational analysis were interpretedin terms of an equilibrium of two conformers in the gas phase. ClC(O)OSO2CF3was prepared by the reaction of ClC(O)SCl with AgOSO2CF3, according to theliterature. The studies were performed using the experimental station for gaseoussamples and coincidence techniques, in the TGM and SGM beamlines at LNLS. Inthe valence electron region, the PEPICO spectra are dominated by signals at m/q= 63/65 and 69, attributable to ClCO+ (with its characteristic isotopic splitting)and CF3+, respectively. If the gaseous sample is irradiated with synchrotron lightof higher energies, several new fragments appear in the spectra, with an increasingimportance of atomic ions for ionization energies corresponding to core-shellelectrons. SO2+, CF2+, SO+, CO2+, CF+, CO+, among others, are the fragmentobserved for irradiation energies in the region of S 2p and Cl 2p electrons, togetherwith ClCO+ and CF3+. In the C 1s, O 1s and F 1s energy regions, atomic fragmentsbecame important in the spectra, being observable also signals originated in doublecharged species (CO22+, Cl2+, F2+, O2+, and C2+). The PEPIPICO spectrahave revealed different photodissociation mechanisms. The most abundant islandsin the spectra correspond to the formation of the following pairs of fragments incoincidence: ClCO+/CF3+, S+/Cl+, and O+/S+, the fragmentation processes canbe interpreted in terms of concerted mechanisms.