Preparation and reactivity of the heterobimetallic ReIr face-shared bioctahedral compounds Cp*Ir(μ-Cl) 3Re(CO) 3 and Cp*Ir(μ-SC 6H 4Me-4) 3Re(CO) 3: X-ray diffraction structures and redox behavior

Abstract

Thermolysis of the dinuclear compound [Cp*IrCl 2] 2 ( 1) with ClRe(CO) 5 ( 2) leads to the formation of the confacial bioctahedral compound Cp*Ir(μ-Cl) 3Re(CO) 3 ( 3) in high yield. Whereas the substitution of the chloride ligands in 3 is observed on treatment with excess p-methylbenzenethiol to furnish the sulfido-bridged compound Cp*Ir(μ-SC 6H 4Me-4) 3Re(CO) 3 ( 4), 3 undergoes fragmentation upon reaction with tertiary phosphines [PPh 3 and P(OMe) 3] to furnish the mononuclear compounds Cp*IrCl 2P and fac-ClRe(CO) 3P 2. Both 3 and 4 have been isolated and fully characterized in solution by IR and 1H NMR spectroscopies, and their solid-state structures have been established by X-ray crystallography. The redox properties of 3 and 4 have been explored by cyclic voltammetry, and the results are discussed relative to extended Hückel MO calculations.