Intramolecular Ion-Molecule Reactions within Ti + (CH 3 COCH 3 ) n Heteroclusters: Oxidation Pathway via C=O Bond Activation

+(CH3COCH3)n heterocluster ions. The reactions of Ti + with CH3COCH3 clusters were found to be dominated exclusively by an oxidation reaction, which produced TiO + (CH3COCH3)n clusters. These ions were attributed to the insertion of a Ti + ion into the C=O bond of the acetone molecule within the heteroclusters, followed by C3H6 elimination. The mass spectra also indicated the formation of minor sequences of heterocluster ions with the formulas Ti + (C3H4O)(CH3COCH3)n and TiO + (OH)(CH3COCH3)n, which could be attributed to C-H bond insertion followed by H2 elimination and to the sequential OH abstraction by the TiO + ion, respectively. Density functional theory calculations were carried out to model the structures and binding energies of both the association complexes and the relevant reaction products. The reaction pathways and energetics of the TiO + + CH2CHCH3 product channel are presented.