GENERATION OF NEW NITRILE N-SULFIDES (NCCNS, R(2)NCNS, H3CSCNS, AND CLCNS) AS IONS AND NEUTRALS IN THE GAS-PHASE - TANDEM MASS-SPECTROMETRY, FLASH VACUUM PYROLYSIS, AND AB-INITIO MO STUDY

1,2,5-Thiadiazoles 1-5 bearing CN, CONH2, SCH3, and Cl substituents ha ve been investigated under electron impact conditions. Collisional act ivation (CA) and neutralizatiun-reionization (NX) mass spectrometries have allowed the identification of new nitrile N-sulfides (NCCNS, H2NC NS, H3CSCNS, and ClCNS) as ions or neutrals in the gas phase of a mass spectrometer, These results were supported by chemical ionization exp eriments of nitriles using carbon disulfide as the reagent gas, flash vacuum pyrolysis experiments, and ab initio molecular orbital calculat ions at the G2(MP2,SVP) level. The neutral nitrile N-sulfides are foun d by experiment and theory to be observable species in the gas phase. All the cations are potential energy minima, and their calculated frag mentation energies are in accord with experimental observations.