Ionic Fragmentation Mechanisms of 2,2,2-Trifluoroethanol Following Excitation with Synchrotron Radiation

YANINA B. BAVA; YANINA BERRUETA MARTÍNEZ; ANGÉLICA MORENO BETANCOURT; MAURICIO F. ERBEN,; REINALDO CAVASSO FILHO; CARLOS O. DELLA VÉDOVA; ROSANA M. ROMANO

Chemphyschem

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2015 vol. 16 p. 322 - 330

1439-4235

Gaseous 2,2,2-trifluoroethanol (TFE) is excited with synchrotron radiation between 10 and 1000 eV and the ejected electrons and positive ions are detected in coincidence. In the valence-electron energy region, the most abundant species is CH2OH+. Other fragments, including ions produced by atomic rearrangements, are also detected; the most abundant are COH+, CFH2+ and CF2H2+. The energies of electronic transitions from C 1 s, O 1 s and F 1 s orbitals to vacant molecular orbitals are determined. A site-specific C 1 s excitation is observed. The photofragmentation mechanisms after the excitation of core-shell electrons are inferred from analysis of the shape and slope of the coincidence between two charged fragments in the bi-dimensional coincidence spectra. The spectra are dominated by islands that correspond to the coincidence of H+ with several charged fragments. One of the most important channels leads to the formation of CH2OH+ and CF3+ in a concerted mechanism.