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

L. R. PIRANI, M. F. ERBEN, M. GERONÉS, CHUNPING MA, M. GE,R. M. ROMANO, R. L. CAVASSO FILHO, Y C.O. DELLA VÉDOVA

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Año: 2010

1089-5639

A study of valence electronic properties of S-ethyl chlorothioformate (S-ethyl chloromethanethioate), ClC(O)SCH2CH3, using HeI photoelectron spectra (PES) and syn-chrotron 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 [photoelectronphotoion coincidence (PEPICO) and photoelectronphotoionpho-toion 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 C2H5þ ion dominates the fragmentation in the valence energy region, the most abundant ion formed in both the S and Cl 2p energy ranges is C2H3þ. 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.