Formation and fragmentation of gas-phase ion-molecule complexes of transition-metal ions with organic molecules containing two functional groups

A mass spectrometer fast atom bombardment source has been used to synthesize, in the gas phase, the ion-molecule complexes of transition-metal ions (Ni⁺, CO⁺, Fe⁺, and Mn⁺) with α- or β-unsaturated alkenenitriles, RCH=CHCN (R=H, CH₃, and C₂H₅) and CH₃CH=CHCH₂CN, and 2-methyl glutaronitrile. The metastable ion fragmentations of the complexes are monitored in the first held-free region by B/E linked scans. Surprisingly, an intense HCN loss via an intermediate (C _n H_2n ?2)?M⁺?(HCN) is observed for the complexes of the alkenenitriles. The metal ions significantly affect the fragmentation processes. The coexistence of both end-on and side-on coordination modes is suggested to explain the fragmentations.