COLLISION-INDUCED DISSOCIATION OF VANADIUM-CARBON CLUSTER CATIONS

Collision-induced dissociation (CID) studies of vanadium−carbon clusters were made employing a triple quadrupole mass spectrometer system coupled with a laser vaporization source. The results reveal that the primary dissociation channel is loss of a metal atom for all but V8C14+, which loses C3, and V9C14+, which loses both V and VC2. These findings are in general agreement with earlier ones reported for the titanium system, except that under single-collision conditions V8C14+ loses a C3 unit to become V8C11+, while Ti8C14+ loses Ti. Importantly, we show that both the met-car V8C12+ and V8C13+ are significantly more resistant to dissociation than the neighboring V8C11+ cluster species. In addition to reporting the primary fragmentation products of several VxCy+ clusters, we also present the results of studies of the multiple-collision dissociation patterns of both V8C12+ and V8C13+, which are observed to undergo C2 and C3 loss after some metal loss has occurred. These findings are consistent with the buil...