A decanuclear Pt complex comprised of an unbridged Pt4 chain capped by two Pt3 A-frame units supported by meso-Ph2PCH2P(Ph)CH2P(Ph)CH2PPh2

Abstract

A linear tetraphosphine meso-bis[(diphenylphosphinomethyl)phenylphosphino]methane (meso-dpmppm), was utilized to prepare a PtI dinuclear complex, [Pt2(μ−meso-dpmppm−κ2,κ1)(XylNC)3](PF6)2 (2), which was derived from reaction of [PtII(meso-dpmppm−κ3)(XylNC)](PF6)2 (1) with 1/3 equiv. of [Pt3(XylNC)6]. Treatment of 2 with 1/3 equiv. of [Pt3(XylNC)6] gave an A-frame Pt3 complex, [Pt3(μ−meso-dpmppm−κ2,κ1)(XylNC)5](PF6)2 (3), demonstrating that a meso-dpmppm ligand effectively support the expansion of platinum nuclearity from Pt2+ through {Pt2}2+ to {Pt3}2+ cores in stepwise fashion. Reaction of 2 with 1 equiv. of meso-dpmppm afforded [Pt2(μ−meso-dpmppm−κ2,κ1)2](PF6)2 (4), which would not react with [Pt3(XylNC)6], and in contrast, treatment of 3 with excess of [Pt3(XylNC)6] gave birth to a decanuclear platinum complex, [Pt10(μ−meso-dpmppm−κ2,κ1,κ1)2(XylNC)18](PF6)6, (5), comprised of a linear Pt4 chain {Pt4(XylNC)8}2+ terminated by two Pt3 A-frame units of {Pt3(μ−meso-dpmppm−κ2,κ1,κ1)(XylNC)5}2+, which is an interesting nano-ordered Pt cluster constructed with small size multinuclear building blocks, and notably contains the longest metal–metal bonded Pt chain without any bridging ligands.