Syntheses of a series of trinuclear MIr2 or pentanuclear MIr4 bimetallic bis(selenido) and selenido–sulfido clusters (M=Pd, Pt, Fe, Co) from diiridium μ-bis(hydroselenido) and μ-hydroselenido–hydrosulfido complexes [{(η5-C5Me5)IrCl}2(μ-SeH)(μ-EH)] (E=Se,

Reactions of a diiridium μ-bis(hydroselenido) complex [Cp*IrCl(μ-SeH)2IrCp*Cl] (1a; Cp*=η5-C5Me5) with [MCl2(cod)] (M=Pd, Pt; cod=1,5-cyclooctadiene), FeCl2, and CoCl2 readily afforded the bimetallic selenido clusters containing a trinuclear or a pentanuclear cores [(Cp*Ir)2(MCl2)(μ3-Se)2] (M=Pd, Pt (5), Fe (6)) and [(Cp*Ir)4Co(μ3-Se)4][CoCl3(MeCN)]2 (8). Cluster 6 was converted to the latter-type bow-tie cluster [(Cp*Ir)4Fe(μ3-Se)4][BPh4]2 (7) by treatment with an additional amount of 1a and excess NaBPh4. 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 H2Se generated in situ from a NaSeH/HCl aq. mixture, followed by that with H2S 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(MCl2)(μ3-Se)(μ3-S)] (M=Pd, Pt, Fe (14)), [(Cp*Ir)2{PtCl(PPh3)}(μ3-Se)(μ3-S)]Cl (13), [(Cp*Ir)4Co(μ3-Se)2(μ3-S)2][CoCl3(MeCN)]2 (15), and [(Cp*Ir)4Fe(μ3-Se)2(μ3-S)2][BPh4]2. To determine the detailed structures, X-ray analyses have been undertaken for 5·1/2ClCH2CH2Cl, 6, 7, 8, 13·CH2Cl2, 14, and 15·CH2Cl2.