PHOTOIONIZATION STUDIES OF SULFUR RADICALS AND PRODUCTS OF THEIR REACTIONS

A discharge flow-photoionization mass spectrometric system coupled to a synchrotron is employed to study intermediates and products of sulfu r radical reactions related to atmospheric chemistry. Sulfur radicals are generated from reactions of oxygen or chlorine atoms with sulfur c ompounds in a flow tube. The gaseous reaction products are sampled int o the ionization region via a three-stage differential pumping scheme. Photoionization spectra and ionization energies are measured by dispe rsing synchrotron radiation to ionize the samples. Using this techniqu e, photoionization spectra and ionization energies of HSO, CH3SO, C2H5 SO, HSCl, and some secondary reaction products, SSCl, HSSCl, HSSSH, CH 3SOH and CH3SS(O)CH3, were measured for the first time.