Synthesis and characterization of bis-(diphenylphosphinoethane) -substituted hexarhodium clusters: Rh 6(CO) 14(μ 2,η 2 -Ph 2P(CH 2) 2PPh 2), Rh 6(CO) 152 (μ 2,η 1 : η 1-Ph 2P(CH 2) 2 PPh 2) and Rh 6(CO) 15(η 1-Ph 2 P(CH 2) 2P(O)Ph 2). X-Ray crystal structures of Rh 6(CO) 15PPh 3 and Rh 6(CO) 14 (μ 2,η 2-Ph 2P(CH 2) 2PPh

Abstract

Two major products of the photoreaction between Rh 6(CO) 16 and bis-(diphenylphosphinoethane) (dppe) were isolated and characterized as Rh 6(CO) 14(μ 2, η 2 -Ph 2P(CH 2) 2 PPh 2) with μ 2-bridging bidentate dppe and Rh 6(CO) 15(η 1-Ph 2P(CH 2) 2P (O)Ph 2) where one P atom of dppe is terminally coordinated, the other being oxidized and thus non-coordinated. Substitution of the labile acetonitrile ligand in Rh 6(CO) 15,NCMe by dppe yields Rh 6(CO) 15 2(μ 2,η 1:η 1-Ph 2P(CH 2) 2PPh 2) with dppe bridging two Rh 6 cores. The structures of Rh 6(CO) 14(μ 2,η 2 -Ph 2P(CH 2) 2PPh 2) and Rh 6(CO) 15PPh 3 have been determined by single-crystal X-ray diffraction studies. Solution structures of Rh 6(CO) 14(μ 2,η 2-Ph 2P(CH 2) 2PPh 2), Rh 6(CO) 15PPh 3, Rh 6(CO) 15(η 1- Ph 2P(CH 2) 2 P(O)Ph 2) and Rh 6(CO) 15 2(μ 2,η 1:η 1-Ph 2P(CH 2) 2PPh 2) have been established by IR, and 13C and 31P NMR spectroscopy.