Binding modes of a mixed donor multidentate iminobisphosphane ligand to the triosmium cluster: the crystal structures of [{Os3(CO)11}2(PNCHP)], [Os3(μ-H)(μ3-PNCP)(CO)7] and [Os3(μ-H)(μ2-PNCP)(CO)8]
摘要:
The triosmium clusters [Os-3(CO)(11)(CH3CN)] and [Os-3(CO)(10)(CH3CN)(2)] react with 2-(diphenylphosphino)-N-[2-(diphenylphosphino)benzylidene]benzeneamine (PNCHP) to give [{Os-3(CO)(11)}(2)(PNCHP)] (1), two coordination isomers of [Os-3(CO)(11)(PNCHP)] (2a) and (2b), and 1,1-[Os-3(CO)(10)(PNCHP)] (3), respectively. When (3) is reacted with trimethylamineoxide the major product is [Os-3(mu-H)(CO)(7)(mu(3)-PNCP)] (4) with two geometrical isomers of [Os-3(mu-H)(CO)(8)(mu(2)-PNCP)] (5a) and (5b) being minor products. The clusters have been fully characterised by spectroscopic means and the structures of 1 . CH2CL2, 4 . 1.5CH(2)Cl(2) and 5a established by single-crystal X-ray analyses. In 1 PNCHP bridges two osmium triangles equatorially. In 4 the imine hydrogen of PNCHP has migrated to the osmium cluster and PNCP acts as a triply bridging nine electron donor, while in 5a PNCP acts as a doubly bridging seven electron donor ligand. (C) 2000 Elsevier Science S.A. All rights reserved.