Synthesis and structural characterization of a dimolybdenum complex bridged by the hydroxymethylphenylphosphinate ligand

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) Å , b = 5.9019(8) Å , c = 8.808(3) Å 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 P21/C space group as a dietherate with a = 9.208(3) Å , b = 14.353(4) Å , c = 12.805(4) Å 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