Outermost and Inner-Shell Electronic Properties of ClC(O)SCH2CH3 Studied Using HeI Photoelectron Spectroscopy and Synchrotron Radiation

RODRIGUEZ PIRANI, LUCAS SEBASTIÁN; ERBEN, MAURICIO FEDERICO; GERONÉS, MARIANA; ROMANO, ROSANA MARIEL; GE, MAO-FA; CAVASSO FILHO, REINALDO; DELLA VÉDOVA, CARLOS OMAR; CHUNPING, MA

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Año: 2011 vol. 115 p. 5307 - 5318

1089-5639

A study of valence electronic properties of S-ethyl chlorothioformate (S-ethyl chloromethanethioate), ClC(O)SCH2CH3, using HeI photoelectron spectra (PES) and  synchrotron radiation is presented. Moreover, the photon impact excitation and dissociation  dynamics of ClC(O)SCH2CH3 excited at the S 2p and Cl 2p levels are elucidated by analyzing the total ion yield (TIY) spectra and time-of-flight mass spectra acquired in multicoincidence mode [photoelectron?photoion coincidence (PEPICO) and photoelectron?photoion?photoion  coincidence (PEPIPICO)]. The HeI photoelectron spectrum is dominated by features associated with lone-pair electrons from the ClC(O)S- group, the HOMO at 9.84 eV being assigned to the nπ(S) sulfur lone-pair orbital. Whereas the formation of C2H5+ ion dominates the fragmentation in the valence energy region, the most abundant ion formed in both the S and Cl 2p energy ranges is C2H3+. Comparison with related XC(O)SR (X = H, F, Cl and R = -CH3, -C2H5) species reveals the impact of the alkyl chain on the photodissociation behavior of S-alkyl (halo)thioformates.