Intramolecular Ion-Molecule Reactions within Ti+(CH3COCH3)n Heteroclusters: Oxidation Pathway via C=O Bond Activation

Abstract

A laser ablation-molecular beam/reflectron time-of-flight mass spectrometric technique was used to investigate the ion-molecule reactions that proceed within Ti+(CH3COCH3)(n) heterocluster ions. The reactions of Ti+ with CH3COCH3 clusters were found to he dominated exclusively by an oxidation reaction, which produced Ti+(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 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 enemies of both the association complexes and the relevant reaction products The reaction pathways and energetics of the Ti++CH2CHCH3 product channel are presented