Homo- and Heteronuclear Complexes of (Pentamethylcyclopentadienyl)rhodium(III) Bearing Bis(diphenylphosphanylmethyl)phenylphosphane

Reaction of [Cp*RhCl2]2 (1) with bis(diphenylphosphanylmethyl)phenylphosphane (dpmp) in the presence of KPF6 generated the mono‐ or bi‐nuclear complexes [(Cp*RhCl)(dpmp‐P,P,P)(RhCl2Cp*)](PF6) (2) or [Cp*RhCl(dpmp‐P,P)](PF6) (3), depending on the reaction conditions. These complexes have two chiral centers at Rh and the central P atoms, and the diastereomers were separated by successive recrystallization. The structures of 2(B) with an RRhSP/SRhRP pair and 3(A) with an RRhSP/SRhRP pair were elucidated by X‐ray analyses. Reaction of 1 with an excess of dpmp in the presence of Ag(OTf) generated a hetero‐tetranuclear complex [{Cp*RhCl2(dpmp‐P,P,P)Ag}2](OTf)2 (4). An X‐ray analysis revealed that each Cp*RhCl2 moiety is connected by a terminal P1 atom of the dpmp ligand and each Ag atom is two‐coordinate and is surrounded by another terminal P3 atom, and a central P*2 atom of the other dpmp ligand. A mixture of 1 and dpmp was treated with Au(SC4H8) or CuCl in the presence of KPF6, generating the hetero‐tetranuclear complexes [{Cp*RhCl2(dpmp‐P,P,P)M}2](PF6)2 (7: M = Au; 8: M = Cu), in which the structures, except for the Cl‐bridged structure of 8, are fundamentally similar to that of 4. These complexes were also prepared by the reactions of 3 with Au(SC4H8) or CuCl. Complex 3 reacted with AgOTf to afford [Cp*Rh(dpmp‐P,P,P)](OTf)2 (5). Treatment of 3(A) (a diastereomer with an RRhSP2/SRhRP2 pair) with 1, [(p‐cymene)RuCl2]2 or PdCl2(cod) gave [Cp*RhCl(dpmp‐P,P,P)RhCl2Cp*](PF6) (2) or [Cp*RhCl(dpmp‐P,P,P)RuCl2(p‐cymene)](PF6) (6), respectively. These addition reactions proceeded stereoselectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)