REACTIONS OF GROUP V TRANSITION METAL OXIDE CLUSTERS WITH 1,3-BUTADIENE

摘要

The reactivities of group V transition metal oxide cluster cations with 1,3-butadiene have been probed using a triple quadrupole mass spectrometer. Most of the group V transition metal oxide clusters form an association product with 1,3-butadiene, M_xO_y~+(C_4H_6). V_2O_(4-5)~+, V_3O_7~+, and V_5O_(12)~+ also react with 1,3-butadiene to form an oxidative dehydrogenation product, V_xO_(y-1)~+(C_4H_4). On the other hand, cleavage of the C2-C3 bond of 1,3-butadiene to produce M_XO_y~+(C_2H_4) is the major reaction pathway for TaO_2~+, Ta_2O_(4-5)_~+, Ta_3O_7~+, NbO_2~+, and Nb_2O_(4-5)~+. Under multiple collision conditions, there were additional cracking channels of Ta_xO_y~+(CH_3) and Ta_xO_y~+(C_3H_4) for a majority of the tantalum oxide clusters studied. Furthermore, niobium and tantalum oxide cluster cations also exhibit multiple addition products during reactions with 1,3-butadiene. In addition, the importance of stoichiometry and size of the cluster in these reactions is considered.