Gas-phase unimolecular reactions of pallada- and nickelalactone anions

Abstract

Electrospray ionization in combination with multistage mass spectrometry experiments in a linear ion trap mass spectrometer was used to generate and study the gas-phase ion chemistry of the metallalactones [(CH 3CO 2)Ni(CH 2CO 2)] - (m/z 175, 5a) and [(CH 3CO 2)Pd(CH 2CO 2)] - (m/z 223, 5b). Low-energy collision-induced dissociation (CID) resulted in decarboxylation to produce novel organometallic ions at m/z 131 (Ni) and m/z 179 (Pd). Isotope labeling experiments, bimolecular gas-phase reactions with allyl iodide, and DFT calculations reveal that decarboxylation primarily occurs from the acetato ligand to yield ions of the form [(CH 3)M(CH 2CO 2)] - (M = Pd, Ni). Further CID experiments on ..