Reactions of phosphines with tetrakis(trifluoroacetato)dimolybdenum(II)

Article abstract of DOI:10.1021/ic50217a059

Reactions of Mo₂(O₂CCF₃)₄ with several phosphines have been examined, and X-ray crystal structures of the products have been determined. Mo₂(O₂CCF₃)₄(PPh₃) ₂ (1) made by the method of Girolami, Mainz, and Andersen (GMA) was found to have the axial diadduct structure assigned to it by GMA, but for technical crystallographic reasons the structure was not fully refined. Crystallographic data for 1 are as follows: space group, P1; a = 9.083 (2), b = 19.897 (6), c = 18.838 (3) ?; α = 134.62 (3), β = 98.34 (2), γ = 94.12 (2)°; V = 2323 (3) ?³; Z = 2. Mo₂(O₂CCF₃)₄(PPhEt₂) ₂ (2) was prepared by reaction in ether and shown by X-ray work to contain nonaxial phosphines which have displaced one oxygen atom of each of two CF₃CO₂ ligands from the molybdenum atoms, to give an Mo₂(OO)₂P₂O₂ core with C_2h symmetry. The Mo-Mo bond length is 2.100 (1) ?. The crystallographic data for 2 are as follows: space group, P1; a = 8.785 (1), b = 11.184(2), c = 11.283 (5) ?; α = 120.89 (2), β = 103.11 (2), γ = 91.50 (1)°; V = 912 (1) ?³; Z = 1. When the reaction of Mo₂(O₂CCF₃)₄ with PPh₂Me was carried out in ether, the only crystalline product isolated was Mo₂(O₂CCF₃)₄(Et₂O) ₂ with the Et₂O molecules axially coordinated. Reaction of Mo₂(O₂CCF₃)₄ with PPh₂Me in toluene gave the crystalline product Mo₂(O₂CCF₃)₄(PPh₂Me) ₂ (3), which has the same type structure as 2 and an Mo-Mo distance of 2.107 (2) ?. Crystal data for this compound are as follows: space group, C2/c; a = 25.898 (4), b = 11.102 (1), c = 17.800 (3) ?; β = 128.55 (1)°; V = 4002 (4) ?³; Z = 4.