CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
congresos y reuniones científicas
Inner shell electronic study of CF3C(O)OC(O)CF3
YANINA B. BAVA; ROSANA M. ROMANO; YANINA BERRUETA MARTÍNEZ; REINALDO L. CAVASSO FILHO; CARLOS O. DELLA VÉDOVA; MAURICIO F. ERBEN
Otro; 26th RAU Annual Users Meeting LNLS; 2016
Laboratório Nacional de Luz Síncrotron
Perfluorinated compounds have been extensively used in industrial applications during the last years. Recently, some perfluorinated species were detected in tissues of animals, in environmental waters, and in the atmosphere.1,2 Different processes may be responsible for the presence of these compounds in the environment. For example, the thermolysis of fluoropolymers and the degradation of fluorotelomer alcohols result in the emission of perfluorocarboxylic species to the atmosphere. In this work, and as part of a general project aimed to the elucidation of the photofragmentation mechanisms of relevant compounds for the atmospheric chemistry,we present the study of trifluoroacetic anhydride using synchrotron radiation with energies between 270 and 715 eV. The photoexcitation and photofragmentation of this species was studied in the SGM beamline at LNLS. The analysis of the Total Ion Yield spectra acquired around the ionization potentials of C 1s, O 1s and F1s, along with the information obtained from quantum chemical calculations, allowed us to assign different resonant electronic transitions. For instance, we could distinguish contributions from different carbon atoms, being the transition C(C==O) 1s → σ*(C−C) approximately 3.5 eV lower in energy than the C(CF3) 1s → σ*(C−C). Moreover, the study of the kinetic energy released by the ions detected in different PEPICO spectra, in combination with the interpretation of the double coincidence islands from a PEPIPICO spectrum were employed to determine different photofragmentation mechanisms. Double coincidences such as C+/CF+, O+/CF+, F+/CF+, CO+/CF+, CO+/CF2+, CO+/CF3+, CF+/CF2+, CF+/CF2+, CF+/CF3+ and CF2+/CF3+ were detected in the PEPIPICO spectra. The mechanisms for these coincidences were proposed based on the shape and slope of the corresponding islands.