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 L. 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, was excited with synchrotron radiation between 10 and 1000 eV and the ejected electrons and positive ions detected in coincidence. In the valence electron energy region the most abundant species was CH2OH+. Other fragments, included ions produced by atomic rearrangements, were also detected. The most abundant are COH+, CFH2+, and CF2H2+. The energies of electronic transitions from C 1s, O 1s, and F 1s orbitals to vacant molecular orbitals (MO´s) were determined. A site specific C 1s excitation was observed. The photofragmentation mechanisms after the excitation of core-shell electrons were inferred from the 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 corresponding 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.