The synthesis and structures of two dimolybdenum(II) complexes that contain derivatives of the 2-(diphenylphosphino)pyridine ligand

The reactions of Mo2(μ-O2CMe)4 with the ligands 2-(diphenylphosphino)-6-(pyrazol-1-yl)pyridine (L1) and 2-chloro-6-(diphenylphosphino)pyridine (L2) in dichloromethane in the presence of HBF4·Et2O afford the complexes trans-[Mo2(μ-O2CMe)2(μ-L1)2](BF4)2 (1) and trans-[Mo2(μ-O2CMe)2(μ-L2)2](BF4)2 (3), respectively, in which the bridging ligands L1 and L2 exhibit P∩N∩N and P∩N coordination to the [Mo2]4+ cores. The compound Mo2(μ-O2CMe)4 reacts with Me3SiCl in the presence of L1 and L2 to give Mo2Cl4(μ-L1)2 (2) and Mo2Cl4(μ-L2)2 (4), respectively. The structural identities of these pairs of complexes have been established by single crystal X-ray structure determinations of 1 and 4.