Bis(hydrosulfido)-bridged dinuclear rhodium(i) complexes as a platform for the synthesis of trinuclear sulfido aggregates with the core [MRh _2(μ_3-S_2)] (M = Rh, Ir, Pd, Pt, Ru)

摘要

The reaction of [Rh(μ-SH)(CO)(PPh_3)]_2 or [Rh(μ-SH){P(OPh)_3}_2]_2 with [Cp*MCl2]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)_2Rh_2(CO) _2(PPh_3)_2] (M = Rh, 1; Ir, 2) and [Cp*Rh(μ_3-S)_2Rh_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_6H_6)RuCl_2]_2 under the same experimental conditions gave [(cod)M(μ_3-S) _2Rh_2{P(OPh)_3}_4] (M = Pd, 6; Pt, 7), [(cod)M(μ_3-S)_2Rh_2(CO)_2(PPh _3)_2] (M = Pd, 8; Pt, 9), [(PPh_3) _2Pt(μ_3-S)_2Rh_2(CO) _2(PPh_3)_2] (10) and [(η~6-C _6H_6)Ru(μ_3-S)_2Rh _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) _2Rh_2{P(OPh)_3}_4] (4) and [Cp*_2ClIr_2(μ_3-S)_2Rh{P(OPh) _3}_2] (5) in a 3:::2 ratio. The RuRh_2 compound [(η~6-C_6H_6)Ru(μ_3-S) _2Rh_2{P(OPh)_3}_4] (11) was prepared similarly from [Rh(μ-SH){P(OPh)_3}_2]_2 and [(η~6-C_6H_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.