From Aggregates to Clusters. Facile Formation of Hetero-Metal−Metal Bonds through Reductive Desulfurization by CO in a Decapacitative Transformation of a {Pt2MS2} Tbp Frame to a {Pt2MS} Tetrahedral Core (M = Ag, Cu, and Ru)

Abstract

[Pt2(PPh3)4(μ-S)2] (1) reacts with AgCl(PPh3) and CuCl under a mild pressure of CO (60 psi) to give [Pt2(CO)(PPh3)3(μ3-S)MCl] [M = Ag (4) and Cu (6)] via the intermediates [Pt2(PPh3)4(μ3-S)2Ag(PPh3)]Cl (2a), [Pt2(PPh3)5(μ3-S)2AgCl] (3), and [Pt2(PPh3)5(μ3-S)2CuCl] (5), respectively. These transformations demonstrate an unprecedented concomitant process which involve heterometalation, carbonylation, reductive desulfurization, and metal−metal bond formation. The Ru−Pt aggregate of [Pt2(PPh3)4(μ3-S)2RuCl(PPh3)2]Cl (7), prepared from 1 and RuCl2(PPh3)3, similarly converts to a [Pt2(CO)2(PPh3)2(μ3-S)RuCl(CO)(PPh3)]Cl (8) cluster under a CO atmosphere. Such transformation establishes a synthetic relationship between the {Pt2MS2} trigonal bipyramidal aggregates and {Pt2MS} tetrahedral clusters and provides a general entry to triangular heterometallic sulfide clusters of platinum. All complexes are characterized by IR, 31P{1H}, and 13C NMR spectroscopy and conductivity measurements. The structures of 4, 6, and th...