Photoionization spectra and ionization energies of HSCl, HSSSH, SSCl, and HSSCl formed in the reaction system Cl/Cl2/H2S

Photoionization-efficiency (PIE) spectra in the wavelength range 110-140 nm were measured for products of the reaction system Cl/Cl-2/H2S in a discharge-flow reactor coupled to a photoionization mass spectrometer employing a synchrotron as source of radiation. According to PIE spectra of HSCl, HSSSH, SSCl, and HSSCl, obtained for the first time, the ionization energies (IE) derived are (9.887+/-0.016), less than or equal to 9.09, (9.04+/-0.03), and (9.266+/-0.014) eV, respectively. Ab initio calculations of these IE with the GAUSSIAN-2 method agree well with experimental results. Other products observed in the system include S-2, HSSH, S-3, and SCl2. Their PIE spectra and IE were also measured; in some cases discrepancies with previous reports are found. The formation mechanism of the observed products is discussed. (C) 1998 American Institute of Physics, [S0021-9606(98)01115-5].