Ionic photofragmentation of ClSO2NCO in the S 2p, Cl 2p and S 2s regions

ANGÉLICA MORENO BETANCOURT; LUCAS S. RODRÍGUEZ PIRANI; MARIANA GERONÉS; MAURICIO F. ERBEN; REINALDO L. CAVASSO FILHO; CARLOS O. DELLA VÉDOVA; ROSANA M. ROMANO

Campinas

Congreso; 21ª Reunião Anual de Usuários (RAU), Laboratório Nacional de Luz Síncrotron; 2001

On the frame of a general project aimed to the elucidation of the photochemical and electronic properties of molecules containing the XSO2 ¡ group, with X = halogen,1 we present here the study of the electronic properties and the dynamic of the ionic photofragmentation of chlorosulfonyl isocyanate, ClSO2NCO, in the S 2p, Cl 2p and S 2s regions. The Total Ion Yield (TIY) spectra of ClSO2NCO in vapour phase were recorded in the TGM beamline at LNLS between 100 and 300 eV, using the vacuum chamber for gaseous samples. Below the S 2p threshold, occurring at approximately 182.8 eV, the TIY spectrum presents a group of ¯ve well defined signals at 170.3, 171.6, 173.2, 174.2 and 175.6 eV and a shoulder at 176.9 eV. A single feature is observed at approximately 208 eV, below the Cl 2p threshold at 214.7 eV. The S 2s edge is also clearly observed as a broad signal at 239 eV. Almost every possible cationic fragment of the parent molecule is observed in the PEPICO spectra, although the relative abundances strongly depend on the excitation energy. The PEPICO spectrum taken at 110 eV, far below the ¯rst S 2p resonance, is dominated by a peak at 106 m/q, which corresponds to SO2NCO+. Also M+, ClSO2 +, SO2 +, SO+, NCO+, among others, are discernable in the spectra. As the excitation energy reaches the S 2p resonance region, the NCO+ and SO+ fragments become more abundant, while at S 2p threshold energy the S+ ion dominates the spectrum. In the PEPICO spectrum measured at 214.7 eV, at the Cl 2p threshold, the Cl+ fragment is the most intense peak. Several double coincidences were detected in the PEPIPICO spectra, revealing diferent fragmentation mechanisms from a double charged molecular ion. The most important pairs of ions detected in coincidences were Cl+/SO2NCO+, NCO+/SO2 +, O+/Cl+, O+/S+, and N+/S+.2 ¡ group, with X = halogen,1 we present here the study of the electronic properties and the dynamic of the ionic photofragmentation of chlorosulfonyl isocyanate, ClSO2NCO, in the S 2p, Cl 2p and S 2s regions. The Total Ion Yield (TIY) spectra of ClSO2NCO in vapour phase were recorded in the TGM beamline at LNLS between 100 and 300 eV, using the vacuum chamber for gaseous samples. Below the S 2p threshold, occurring at approximately 182.8 eV, the TIY spectrum presents a group of ¯ve well defined signals at 170.3, 171.6, 173.2, 174.2 and 175.6 eV and a shoulder at 176.9 eV. A single feature is observed at approximately 208 eV, below the Cl 2p threshold at 214.7 eV. The S 2s edge is also clearly observed as a broad signal at 239 eV. Almost every possible cationic fragment of the parent molecule is observed in the PEPICO spectra, although the relative abundances strongly depend on the excitation energy. The PEPICO spectrum taken at 110 eV, far below the ¯rst S 2p resonance, is dominated by a peak at 106 m/q, which corresponds to SO2NCO+. Also M+, ClSO2 +, SO2 +, SO+, NCO+, among others, are discernable in the spectra. As the excitation energy reaches the S 2p resonance region, the NCO+ and SO+ fragments become more abundant, while at S 2p threshold energy the S+ ion dominates the spectrum. In the PEPICO spectrum measured at 214.7 eV, at the Cl 2p threshold, the Cl+ fragment is the most intense peak. Several double coincidences were detected in the PEPIPICO spectra, revealing diferent fragmentation mechanisms from a double charged molecular ion. The most important pairs of ions detected in coincidences were Cl+/SO2NCO+, NCO+/SO2 +, O+/Cl+, O+/S+, and N+/S+.