Reactivity of acetone oxime towards oxomolybdenum(VI) complexes. Part 1. Syntheses and crystal structures of tetranuclear molybdenum(VI) complexes
Abstract
Reaction of acetone oxime with [NBun4]4[α-Mo8O26] in refluxing methanol yielded [NBun4]2[Mo4O12(Me2CNO)2]1 while that with [MoO2(acac)2](acac = acetylacetonate) at room temperature resulted in the formation of [Mo4O10(OMe)4(Me2CNHO)2]2. The crystal structures of 1 and 2 have been determined [1, space group P, a= 9.009(1), b= 17.860(1), c= 16.769(1)Å, α= 91.624(5), β= 101.158(7), γ= 91.983(7)°, R= 0.037 for 7429 reflections with I > 3σ(I); 2, space group P21/c, a= 9.437(1), b= 8.827(1), c= 13.727(3)Å, β= 92.15(1)°, R= 0.029 for 2821 reflections with I > 3σ(I)]. The anion of 1 displays a cyclic (MoO2)4(µ-O)4 ring while 2 displays a MoVI4(µ3-OMe)2 central core. The µ4-κ2N:κ2O co-ordination mode exhibited by the acetone oximate in 1 is unprecedented for such a ligand, so is the end-on co-ordination mode of zwitterionic acetone oxime in 2. The reactivity of 1 and 2 respectively towards hydrochloric acid and tetrabutylammonium hydroxide was studied.