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Treatment of ZrCl4 with 3 equiv. of Li(PPh2NR) (R = tBu, iPr) gives tris(phosphinoamide)zirconium complexes, (PPh2NR)3ZrCl [R = tBu (1a), iPr (1b)], in high yield. Crystal structures of 1a,b show that three phosphorus atoms are coordinated to the zirconium center in the solid state, whereas variable temperature NMR studies indicate a reversible coordination/dissociation process of three phosphorus atoms in the solution state. Reaction of 1a,b with CuCl give rise to the formation of Zr–Cu heterodimetallic complexes, ClCu(Ph2PNR)3ZrCl [R = tBu (2a), iPr (2b)]. The molecular structures of 2a,b show that the Cu atom adopts a pseudotetrahedral coordination geometry with tripodal phosphorus moieties and a chlorine atom, whereas the ligand arrangement around the Zr atom is trigonal bipyramidal with the linear Cl–Zr–Cu axis at the apical site. A Zr–Mo heterodimetallic complex, (CO)3Mo(Ph2PNiPr)3ZrCl (3), is synthesized from 1b and Mo(CO)3(CH3CN)3, in which the ligands around the Mo center are arranged octahedrally, and three phosphorus moieties are coordinated in the fac-P3 fashion. The reaction of 1b with a square planar PtII precursor, such as (COD)PtCl2, is unique and gives (κ2-Ph2PNiPr)Pt(Ph2PNiPr)2ZrCl3 (4), which is the first example of a Zr–Pt zwitterionic heterodimetallic complex. The reaction involves intramolecular migration of two chlorine atoms from Pt to Zr as well as that of a Ph2PNiPr moiety from Zr to Pt.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

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)