Fragmentation Mechanisms of Trifluoroethanol, CF3CH2OH, following Photoexcitation with Synchrotron Radiation between 100 and 1000 eV

YANINA B. BAVA; REINALDO L. CAVASSO FILHO; CARLOS O. DELLA VÉDOVA; MAURICIO F. ERBEN; MARIANA GERONÉS; ANGÉLICA MORENO BETANCOURT; ROSANA M. ROMANO

Campinas

Otro; 23ª Reunião Anual de Usuários do LNLS/CNPEM; 2013

Laboratório Nacional de Luz Síncrotron

Fluorinated alcohols are industrial alternative compounds for chlorofluorocarbonsand hydrochlorofluorocarbons, species responsible for ozone depletion in thestratosphere and with high global warming potentials. Although Trifluoroethanolpresents a wide variety of industrial applications, going from pharmaceutical usesas starting material for some inhalation anesthetics, in the preparation and treatmentof nylon, as working fluid for heat engines, between others, studies regardingits potential environmental impact are still scarce. In this work, and as part of ageneral project aimed to the elucidation of the photofragmentation mechanismsusing synchrotron radiation of compounds relevant for atmospheric chemistry, wepresent here the study of Trifluoroethanol using synchrotron radiation between 100and 1000 eV. Photoionization and photofragmentation of Trifluoroethanol in theenergy region between 100 and 1000 eV were studied in the SGM beamline atLNLS, using the experimental station for gaseous samples and coincidence techniques.Photoelectron-Photoion-Coincidence (PEPICO) spectra were taken at eachresonance, and bellow and above every resonance. The most intense signals in thePEPICO spectra are the ones assigned to H+, COH+, and the peak at m/z = 31,that may corresponds to CH2OH+, CF+, or both. Features arising from C+, F+,CF2+, CF3+ and OH+ fragments are also important in the spectra. It is worthto mention the presence of several ions, with relative intensities between 1 and 5%, explained only by atomic rearrangements: CH3+, H2O+, FH+, C2H3+, CFH+, CH2F+, FO+ y F2+. The PEPIPICO spectra are dominated by islands correspondingfor the coincidence of H+ with almost all the possible charged fragments. Oneof the most important channels leads to the formation of H+ and CF3+ in a concertedmechanism. Other examples are the coincidences between CF+/CH2O+ andCF2+/CHO+, that follow Differed Charge Separation mechanisms.