Synthesis and solid state structure of bis(μ-acetate)bis( p-methylbenzyl)bis(trimethylphosphine)-dimolybdenum (MoMo), Mo 2(O 2CCH 3) 2(CH 2Ph- p-Me) 2(PMe 3) 2

Abstract

The reaction of Mo 2(OAc) 4[OAcO 2CCH 3] with 2 equivalents of Mg(CH 2Ph- p-Me) 2 (CH 2Ph- p-Me = p-methylbenzyl) in the presence of PMe 3 has led to the isolation of the acetate bridged dimer Mo 2(OAc) 2(CH 2Ph- p-Me) 2(PMe 3) 2 as deep pink crystals which have been studied by X-ray diffraction methods. Crystal data for Mo 2P 2O 4C 26H 42, M r = 672.45, P 1 , a = 9.476(6), b = 11.828(3), c = 15.202(3) Å; α = 96.89(2), β = 97.27(4), γ = 111.18(4)°, V = 1550(2) Å 3, Z = 2, D x = 1.440 g cm −3, Mo Kα, λ = 0.71703 Å, μ = 9.17 cm −1, F(000) = 688.0, T = 24.0 °C, R = 0.060 for 4043 unique observation reflections. The unit cell contains two independent but essentially identical molecules. The structures consist of two molybdenum atoms bridged by two acetate molecules with a terminally bound benzyl and phosphine ligand at each metal center. The coordination geometry at each metal is approximately tbp, with a MM distance consistent with a bond order of four.