CEQUINOR   05415
CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Fragmentation Mechanisms of Trifluoroethanol, CF3CH2OH, following Photoexcitation with Synchrotron Radiation between 100 and 1000 eV.
Autor/es:
BAVA YANINA BELÉN; DELLA VÉDOVA CARLOS O.; ERBEN MAURICIO F.; GERONÉS MARIANA; ANGÉLICA MORENO BETANCOURT; ROMANO ROSANA M.
Lugar:
Sao Pablo
Reunión:
Congreso; 23 Reunión Anual de Usuarios del LNLS, Campinas, Brasil.; 2013
Institución organizadora:
Laboratorio Nacional de Luz Sincrotrón
Resumen:
Fragmentation Mechanisms of Trifluoroethanol following Photoexcitation with Synchrotron Radiation between 100 and 1000 eV Bava Yanina1, Cavasso Filho, R. L.2, Della V´edova, Carlos O.1, Erben, Mauricio F.1, Geron´es, Mariana1, Angelica Moreno Betancourt1, and Romano, Rosana M.1 1 Universidad Nacional de La Plata - La PLata B.A. Argentina 2 Universidade Federal do ABC - Santo Andr´e SP Brazil Fluorinated alcohols are industrial alternative compounds for chlorofluorocar- bons and hydrochlorofluorocarbons, species responsible for ozone depletion in the stratosphere and with high global warming potentials. Although Trifluoroethanol presents a wide variety of industrial applications, going from pharmaceutical uses as starting material for some inhalation anesthetics, in the preparation and treat- ment of nylon, as working fluid for heat engines, between others, studies regarding its potential environmental impact are still scarce.1 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, we present here the study of Trifluoroethanol using synchrotron radiation between 100 and 1000 eV. The purity of a commercial sample of 2,2,2-trifluoroethanol, CF3CH2OH, was confirmed by means of its vapour-phase IR spectrum. Photoion- ization and photofragmentation of Trifluoroethanol in the energy region between 100 and 1000 eV were studied in the SGM beamline at LNLS, using the exper- imental station for gaseous samples and coincidence techniques.2 The Total Ion Yield (TIY) spectra following C 1s excitations presents two resonances below the threshold energy occurring at 294.5 eV. In the O 1s region, peaks near 534 and 537 eV are observed as the most prominent features of the spectra, while the spectra in the F 1s region exhibit a unique signal near 692 eV. Photoelectron-Photoion- Coincidence (PEPICO) spectra were taken at each resonance, and bellow and above every resonance. The observed pattern is almost independent of the incident radi- ation, denoting the absence of site specific fragmentation. The most intense signals in the PEPICO 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 worth to 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+.
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