Preparation and characterization of palladium and platinum complexes bearing 1,8-bis[(diphenylphosphino)methyl]naphthalene

Abstract

Reaction of MCl2(cod) (M = Pd, Pt) with 1,8-bis[(diphenylphosphino)methyl]naphthalene (1,8-dpmn) gave MCl2(1,8-dpmn) 1 (M = Pd), 2 (M = Pt), as confirmed by X-ray analyses. Complex 1 reacted with xylyl isocyanide a (XylNC) in the presence of NaPF6 to give [Pd(1,8-dpmn)(XylNC)2](PF6)23a. Reactions of dinuclear complexes [M2(RNC)6](PF6)2 (4: M = Pd, 5: M = Pt; R = Xyl (a) or 2,4,6-Me3C6H2 (b) (Mes)) with one or two equiv. of 1,8-dpmn gave [M2(1,8-dpmn)(RNC)4](PF6)26 (M = Pd) and 7 (M = Pt), or [M2(1,8-dpmn)2(RNC)2](PF6)28 (M = Pd) and 9 (M = Pt). The structures of 6b, 7b and 8b were confirmed by X-ray analyses. Reaction of [Pd2Cl2(XylNC)4] with two equiv. of 1,8-dpmn in the presence of NaPF6 gave 8a, whereas the reaction in the presence of NH4PF6 produced 10a together with 7a. It was confirmed by an X-ray analysis of 10a that the crystal lattice is constructed by two types of cations (3a and two 2,2,6,6-tetramethyl-4-piperidonium) and four PF6 anions. Photochemical reaction of 6a or 8a in CH2Cl2 led to cleavage of the Pd–Pd bond, giving [PdCl(XylNC)3](PF6) and [PdCl(1,8-dpmn)(XylNC)](PF6).