Bis(hydrosulfido)-bridged dinuclear rhodium(i) complexes as a platform for the synthesis of trinuclear sulfido aggregates with the core [MRh2(μ3-S2)] (M = Rh, Ir, Pd, Pt, Ru)

Abstract

The reaction of [Rh(μ-SH)(CO)(PPh(3))](2) or [Rh(μ-SH){P(OPh)(3)}(2)](2) with [Cp*MCl(2)](2) (M = Rh, Ir) in the presence of NEt(3) afforded the Rh(3) and IrRh(2) sulfido-bridged compounds [Cp*M(μ(3)-S)(2)Rh(2)(CO)(2)(PPh(3))(2)] (M = Rh, 1; Ir, 2) and [Cp*Rh(μ(3)-S)(2)Rh(2){P(OPh)(3)}(4)] (3). The reaction with [MCl(2)(cod)] (M = Pd, Pt), cis-[PtCl(2)(PPh(3))(2)] or [(η(6)-C(6)H(6))RuCl(2)](2) under the same experimental conditions gave [(cod)M(μ(3)-S)(2)Rh(2){P(OPh)(3)}(4)] (M = Pd, 6; Pt, 7), [(cod)M(μ(3)-S)(2)Rh(2)(CO)(2)(PPh(3))(2)] (M = Pd, 8; Pt, 9), [(PPh(3))(2)Pt(μ(3)-S)(2)Rh(2)(CO)(2)(PPh(3))(2)] (10) and [(η(6)-C(6)H(6))Ru(μ(3)-S)(2)Rh(2)(CO)(2)(PPh(3))(2)] (12), with PdRh(2), PtRh(2) and RuRh(2) trimetallic cores. The aggregates derived from [Rh(μ-SH)(CO)(PPh(3))](2) were isolated as a mixture of trans and cis isomers in which the trans isomer predominates. The reaction of [Rh(μ-SH){P(OPh)(3)}(2)](2) with 2 equiv. of n-BuLi at 253 K followed by addition of [Cp*IrCl(2)](2) gave [Cp*Ir(μ(3)-S)(2)Rh(2){P(OPh)(3)}(4)] (4) and [Cp*(2)ClIr(2)(μ(3)-S)(2)Rh{P(OPh)(3)}(2)] (5) in a 3 : 2 ratio. The RuRh(2) compound [(η(6)-C(6)H(6))Ru(μ(3)-S)(2)Rh(2){P(OPh)(3)}(4)] (11) was prepared similarly from [Rh(μ-SH){P(OPh)(3)}(2)](2) and [(η(6)-C(6)H(6))RuCl(2)](2) using n-BuLi as a deprotonating agent. The molecular structures of compounds 3, 6, 7, 9 and 11 have been determined by X-ray analysis. The trinuclear complexes exhibit an asymmetric triangular metal core with two triply bridging sulfido ligands resulting in a distorted trigonal-bipyramidal M(3)(μ(3)-S)(2) heterometallic metal-sulfur core.