Syntheses of a series of trinuclear MIr 2 or pentanuclear MIr 4 bimetallic bis(selenido) and selenido–sulfido clusters (M=Pd, Pt, Fe, Co) from diiridium μ-bis(hydroselenido) and μ-hydroselenido–hydrosulfido complexes [{(η 5-C 5Me 5)IrCl} 2(μ-SeH)(μ-EH)] (E=Se, S)

Abstract

Reactions of a diiridium μ-bis(hydroselenido) complex [Cp*IrCl(μ-SeH) 2IrCp*Cl] ( 1a; Cp*=η 5-C 5Me 5) with [MCl 2(cod)] (M=Pd, Pt; cod=1,5-cyclooctadiene), FeCl 2, and CoCl 2 readily afforded the bimetallic selenido clusters containing a trinuclear or a pentanuclear cores [(Cp*Ir) 2(MCl 2)(μ 3-Se) 2] (M=Pd, Pt ( 5), Fe ( 6)) and [(Cp*Ir) 4Co(μ 3-Se) 4][CoCl 3(MeCN)] 2 ( 8). Cluster 6 was converted to the latter-type bow-tie cluster [(Cp*Ir) 4Fe(μ 3-Se) 4][BPh 4] 2 ( 7) by treatment with an additional amount of 1a and excess NaBPh 4. Novel μ-hydroselenido–hydrosulfido complex [Cp*IrCl(μ-SeH)(μ-SH)IrCp*Cl] ( 3) was obtained by the reaction of [Cp*IrCl(μ-Cl) 2IrCp*Cl] with one equiv of H 2Se generated in situ from a NaSeH/HCl aq. mixture, followed by that with H 2S gas. Treatment of 3 with a range of transition metal compounds has shown that 3 can serve as a good precursor to synthesize a series of mixed-chalcogenido clusters in a rational manner; selenido–sulfido clusters derived from 3 include [(Cp*Ir) 2(MCl 2)(μ 3-Se)(μ 3-S)] (M=Pd, Pt, Fe ( 14)), [(Cp*Ir) 2{PtCl(PPh 3)}(μ 3-Se)(μ 3-S)]Cl ( 13), [(Cp*Ir) 4Co(μ 3-Se) 2(μ 3-S) 2][CoCl 3(MeCN)] 2 ( 15), and [(Cp*Ir) 4Fe(μ 3-Se) 2(μ 3-S) 2][BPh 4] 2. To determine the detailed structures, X-ray analyses have been undertaken for 5·1/2ClCH 2CH 2Cl, 6, 7, 8, 13·CH 2Cl 2, 14, and 15·CH 2Cl 2.