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 H2n -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.