Electronic Properties of FC(O)SCH2CH3. A Combined Helium(I) Photoelectron Spectroscopy and Synchrotron Radiation Study

LUCAS S. RODRÍGUEZ PIRANI; MAURICIO F. ERBEN; MARIANA GERONÉS; ROSANA M. ROMANO; REINALDO L. CAVASSO FILHO; CHUNPING MA; MAOFA GE; CARLOS O. DELLA VÉDOVA

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Lugar: Washington; Año: 2014 vol. 118 p. 5950 - 5960

1089-5639

The valence electronic properties of S-ethyl flouromethanethioate (Sethylfluoromethsanethioate), FC(O)SCH2CH3, were investigated by means of He(I)photoelectron spectroscopy in conjunction with the analysis of the photofragmentationproducts determined by PEPICO (phtoelectron-photoion-coincidence) by usingsynchrotron radiation in the 11.1−21.6 eV photon energy range. The first bandobserved at 10.28 eV in the HeI photoelectron spectrum can be assigned withconfidence to the ionization process from the HOMO [nπ(S) orbital], which isdescribed as a lone pair formally localized on the sulfur atom, in agreement withquantum chemical calculations using the outer valence Green function method [OVGF/6-311++G (d,p)]. One of the most important fragmentation channels also observed inthe valence region corresponds to the decarbonylation process yielding the [M−CO]·+ion, which is clearly observed at m/z = 80. Moreover, S 2p and S 2s absorption edgeshave been examined by measuring the total ion yield spectra in the 160−240 eV regionusing variable synchrotron radiation. The dynamic of ionic fragmentation following theAuger electronic decay has been evaluated with the help of the PEPIPICO (photoion−photoion−photoelectron−coincidencespectra) technique.