Aufbau approach to multimetallic ensembles based on tetrathiooxalate:: [Cp*4Rh4(C2S4)2]2+, [Cp*3Rh2Ru(C2S4)]+ and [Cp*6Rh6(C2S4)2]4+

Experiments aimed at the characterization of new coordination modes for tetrathiooxalate (TTO) are described. Cyclic voltammetric (CV) measurements on Cp*Rh-2(2)(C2S4) (1) revealed an irreversible oxidation as part of an ECE process that results in the chemically reversible; dimerization of 1(+). Treatment of 1 with CpFe[C5H4C(O)Me]BF4 followed by anion exchange gave [Cp*Rh-4(4)(C2S4)(2)](BPh4)(2), the dicatiori of which consists of a dimer of is linked through two pairs of Rh-S bonds. A second new bonding mode for TTO was generated by treatment of 1 with [Cp*Ru(MeCN)(3)]PF6 to give [Cp*3Rh2Ru(C2S4)](+) (3) wherein Cp*Ru+ is eta (5)-bonded to one RhS2C2 ring. A third new bonding mode for TTO is illustrated by [Cp*Rh-6(6)(C2S4)(2)](4+), formed by the reaction of Cp*Rh(MeCN)(3)(2+) and 1. The structure can be viewed as a dimer of 3, except that there are no M-M bonds: the Cp*Rh2+ fragments are bonded via an eta (4)-interaction to RhS2C2 rings. Furthermore, the [Cp*Rh-3(3)(C2S4)](2+) subunits, which are otherwise isoelectronic with 3, dimerize, such that all eight sulfur atoms are triply bridging.