CHARACTERIZATION OF NEW CUMULENES C(2)NX(2) (X=O OR S) - TANDEM MASS-SPECTROMETRY AND AB-INITIO STUDIES

New cumulenic ions, SNCCO+, SCNCO+, SNCCS+, and SCNCS+, have been gene rated by dissociative ionization and characterized by tandem mass spec trometry techniques. The stabilities of the corresponding radicals wer e evaluated by neutralization-reionization (NR) experiments and suppor ted by ab initio molecular orbital calculations at the G2(MP2,SVP) lev el. The neutral radicals, SNCCS., SCNCS., and SNCCO., are found by exp eriment and theory to be observable species in the gas phase, while SC NCO. is not accessible under NR conditions. All the cations are potent ial energy minima, and their calculated fragmentation energies are in reasonable accord with experiment.