Formation of HCO+ and HCS+ Ions in the Photodissociation of CH3OC(S)SCH3 under VUV Synchrotron Radiation

RODRÍGUEZ PIRANI, LUCAS S.; CÁNNEVA, ANTONELA; GERONÉS, MARIANA; DELLA VÉDOVA, CARLOS O.; ROMANO, ROSANA M.; CAVASSO-FILHO, REINALDO; ERBEN, MAURICIO F.

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Año: 2019 vol. 123 p. 6674 - 6682

1089-5639

Synchrotron-based Total Ion Yield (TIY) and PhotoElectron-PhotoIon-Coincidence (PEPICO) spectra have been applied to investigate the electronic structure and the dissociative ionization of gaseous O,S-dimethyl xanthate, CH3OC(S)SCH3, in the shallow-core S 2p region. The use of tunable synchrotron radiation allows for a selective excitation of sulfur atoms at different photon energy values, including resonance transitions and ionization around the S 2p level. Total ion yield spectrum has been measured varying the energy from 160 to 180 eV and several photodissociation channels have been determined. The fragmentation patterns show that the title molecule is well suited as a laboratory precursor of ionic species found in the interstellar medium, especially formyl and thioformyl cations, HCO+ and HCS+, respectively.