Synthesis and Structural Characterization of a Dimolybdenum Complex Bridged by the Hydroxymethylphenylphosphinate Ligand

Abstract  

Hydroxymethylphenylphosphinic acid, 1 was synthesized and structurally characterized by single crystal X-ray diffraction. Ligand 1 crystallized in the monoclinic P2₁ space group with two molecules comprising the unit cell and cell dimensions a = 7.5587(13) ?, b = 5.9019(8) ?, c = 8.808(3) ? and β = 90.90(2)°. Molecules were linked up by hydrogen bonding involving all three oxygen atoms of 1 resulting in 2-dimensional sheets. Reacting 1 with MoO₂Cl₂ in a mixture of ethanol and dichloromethane afforded the dinuclear molybdenum complex Mo₂O₄Cl₂(HOCH₂)PhPOO]₂, 2 where the two molybdenum atoms were bridged by the phosphinate ligand. Complex 2 crystallized in the P2_1/C space group as a dietherate with a = 9.208(3) ?, b = 14.353(4) ?, c = 12.805(4) ? and β = 98.64(3)° and contained terminal O and Cl atom disorder. The two crystallographically identical molybdenum centers are in distorted octahedral environments. Complexes were analyzed by IR, ³¹P NMR and X-ray crystallography.