Thermal Reactions of (V₂O₅)_<i>n</i>O^–(<i>n</i>= 1–3) Cluster Anions with Ethylene and Propylene: Oxygen Atom Transfer Versus Molecular Association

Abstract

Vanadium oxide cluster ions are prepared by laser ablation and the (V 2 O 5 ) n O – ( n = 1–3) clusters (V 2 O 6 –, V 4 O 11 –, and V 6 O 16 – ) are selected by a quadrupole mass filter and interacted with ethylene (C 2 H 4 ) and propylene (C 3 H 6 ) in an ion trap reactor. Molecular association (MA) is observed for all of the reactions and oxygen atom transfer (OAT) is also observed for the V 4 O 11 – and V 6 O 16 – cluster systems. The branching ratio of the OAT versus the MA channel increases as the size of (V 2 O 5 ) n O – increases and the OAT becomes the major channel in V 6 O 16 – + C 2 H 4 and V 6 O 16 – + C 3 H 6 . Density functional theory computations are carried out for the reactions of V 2 O 6 – and V 4 O 11 – with C 2 H 4 and the results are consistent with the experimental observations. Anionic metal oxide clusters are usually much less reactive than their cationic and neutral counterparts and this work is among the first to identify the OAT reactivity for cluster anions with hydrocarbon molecules under thermal collision conditions, to the best of our knowledge.