Rhodium(I) Complexes with a n1- Fluorenyl, P -Phosphanyl-Phosphorane Ligand

Abstract

The first example of a P-phosphanylphosphorane, Flu�PCy2−PCy2 (L2; Flu = 9-fluorenyl), has been easily prepared by P-phosphination of lithiated 9-dicyclohexylphosphinofluorene (FluPCy2, L0) with chlorodicyclohexylphosphane. L2 constitutes a new type of P(III)−P(V) organophosphorus compound, a σ3 λ3 −σ4 λ5 species that is stable under an inert atmosphere in the solid state. The reaction of L2 with [Rh(diene)2]BR4 causes metalation of the benzylic carbon (C9) of fluorene, giving κ2 -C,P complexes in which fluorene is coordinated in the η1 form. A complex with the weakly coordinating BArF anion has been isolated and fully characterized, including its crystal structure obtained by X-ray diffraction.