Intracluster ion-molecule reactions of V +(CH 3COOR) n (R = CH 3, C 2H 5, C 2D 5) complexes produced by the mixing of laser-vaporized plasmas and pulsed supersonic beams were investigated by reflectron time-of-flight mass spectrometry. The mass spectra indicated the presence of a major sequence of cluster ions with the formula V +(CH 3COO)(CH 3COOR) n. This sequence is attributed to the insertion of V + into the CO bond of CH 3COOR within the heteroclusters, followed by alkyl radical (R) elimination. The observation of V +(OR) and V +(CH 3)(OR) ions is interpreted as arising from the insertion of V + into the C(O)O bond of the ester group, followed by CH 3CO and CO elimination, respectively. In addition, the VO + ion is present throughout the mass spectra, indicating that insertion of V + into the CO bond of CH 3COOR also occurs. Within the stabilizing environs of a heterocluster, sequential insertions of VO + ions into a second molecule produced VO +(CH 3COO)(CH 3COOR) n and VO +(CH 3)(OR)(CH 3COOR) n heteroclusters via reaction pathways similar to those of the V + ion. The results of isotope-labeling experiments suggest that the reaction pathway for formation of V +(CH 3COOH)(CH 3COOC 2H 5) n involves V + insertion into the CO bond of ethyl acetate, followed by β-H atom transfer from the ethyl group. 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 each product channel are presented.
Bibliographical noteFunding Information:
This work was supported by the Basic Science Research Program 2009-0068446 and 2010-0006570 through the National Research Foundation of Korea (NRF) , funded by the Ministry of Education, Science and Technology . One of the authors (K.-W. Jung) also gratefully acknowledges the Basic Science Research Program (2010-0008852) through the NRF funded by the Ministry of Education, Science and Technology.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physical and Theoretical Chemistry