Preparation and reactivity of the heterobimetallic ReIr face-shared bioctahedral compounds Cp*Ir(μ-Cl)3Re(CO)3 and Cp*Ir(μ-SC6H4Me-4)3Re(CO)3: X-ray diffraction structures and redox behavior

Thermolysis of the dinuclear compound [Cp*IrCl2]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-SC6H4Me-4)3Re(CO)3 (4), 3 undergoes fragmentation upon reaction with tertiary phosphines [PPh3 and P(OMe)3] to furnish the mononuclear compounds Cp*IrCl2P and fac-ClRe(CO)3P2. 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.

Thermolysis of [Cp*IrCl2]2 (1) with ClRe(CO)5 (2) gives the chloride-bridged compound Cp*Ir(μ-Cl)3Re(CO)3 (3), which when treated with excess HSC6H4Me-4 yields the sulfido-bridged product Cp*Ir(μ-SC6H4Me- 4)3Re(CO)3 (4). Compounds 3 and 4 have been spectroscopically characterized and their molecular structures established by X-ray crystallography.Figure optionsDownload as PowerPoint slide