Syntheses of reactive multinuclear metal complexes using various phosphorus ligands as a bridge

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Dinuclear complexes have attracted continuous interest, since two metal centers in close proximity may provide a reaction site where both metals are engaged in multisite interactions with a substrate and/or consecutive activation and transformation of a substrate. In this project, novel phosphorus ligands were synthesized as a linker which can bridge two metal fragments having useful functionalities.Py-P-Fc Bridge. A phosphorus-bridged [1]ferrocenophane having a pyridine arm, Py-CH(Ph)-P(C_<10>H_8Fe) 1, was prepared as a precursor ligand. A tungsten complex having this strained phospha-heterocyle ligand, W(CO)_4(1), reacts with a Pd(PMe_3)_2 fragment to give a W-Pd complex(OC)_4W{μ-λN, P, C-PyCH(Ph)P(C_<10>H_8Fe)}Pd(PMe_3)_2 in which the Pd fragment inserts into a strained P-C bond. The complex was found to exhibit a selective ligand substitution at a coordination site where the two metal centers can interact simultaneously.P_2B_2 Bridge. An unprecedented aggregate of a transition-meta … More lated phosphinoborane was prepared. Cp(CO)_2Fe{P(BCl_3)HPh} was treated with n-BuLi to yield an iron-phosphinoborane dimer, μ-(PhPBCl_2)_2[Cp(C0)_2Fe]_2 2, via a dehydrohalogenation reaction. The X-ray structural study of 2 revealed that the dimer has a bent P_2B_2 4-membered ring.P-P Bridge. A bisphosphine in which a robust naphthalene group supports a P-P bond, 1,2-dihydro- 1,2-diphenyl-naphtho[1,8-c, d]1,2-diphosphole 3, was used as a bridging ligand for the preparation of dinuclear group 6 metal complexes. An M-P-P-M framework thus formed, μ-3-[W(C0)_5]_2, exhibited a thermal stability as expected.Cp-P-Cp Bridge. UV-Vis irradiation of P(=S)Ph-bridged [1]ferrocenophane, [Fe{(η^5-C_5H_4)_2P(=S)Ph}] in the presence of P(OMe)_3 gave a ring-slipped product, [Fe{(η^5-C_5H_4)(η^1-C_5H_4)P(=S)Ph}{P(OMe)_3 }_2] 4. When 4 having an,η^1-C_5H_4 group was allowed to react with [M(CO)_3(NCMe)_3] (M = Mo, W), iron-molybdenum and-tungsten heterodinuclear complexes μ{η^5, η^5-(C_5H_4)_2P(=S)Ph-kS}-[Fe{P(OMe)_3}_2][M(C0)_3] (M = Mo 5-Mo, W 5-W) were obtained, in which the two metal fragments were linked with an η^5-C_5H_4P(=S)Ph(η^5-C_5H_4)-kS bridge. In addition, 5-Mo and 5-W were readily converted in acetonitrile to the respective acetonitrile complexes μ-{ η^5,η^5-(C_5H_4)_2P(=S)Ph}-[Fe(NCMe){P(0Me)_3 }_2][M(C0)_3] with the P=S group giving up coordination to the iron center. Less