Modified synthesis of mixed-ligand dinuclear Ru–Ir, Ru–Rh, and Ru–Ru polyhydride-bridged complexes, CpsRuH3ML (Cps = C5Me5 (Cp*), C5tBu3H2 (Cp‡); M = Rh, Ir, Ru; L = C5(CH3)5, C6H6, p-CH3C6H4CH(CH3)2)

• Hetero-bimetallic trihydride complexes were efficiently synthesized.
• Polyhydride clusters containing C5(tBu)3H2 and arene ligands were synthesized.
• The hydrides were simply introduced with 2-propanol in the presence of a base.
• The hetero-bimetallic chloride complexes were used as a starting material.

Hetero-bimetallic polyhydride clusters exhibit a regio- and chemoselective activation of a substrate. The rational synthetic method for hetero-bimetallic polyhydride complexes using readily available halide complexes is reported. The reaction of hetero-bimetallic Ru–Ir trichloride complex, Cp*Ru(μ-Cl)3IrCp* (5a), in 2-propanol in the presence of a base afforded Cp*Ru(μ-H)3IrCp* (6a) by sequential salt metathesis and β-hydrogen elimination. CpsRu(μ-H)3ML [Cps = Cp*, Cp‡; ML = IrCp*, RhCp*, Ru(p-cymene), Ru(benzene)] were also selectively synthesized by reacting a mixture of CpsRuCl/n and [LM(μ-Cl)Cl]2 via the formation of CpsRu(μ-Cl)3ML. The IrCp*, RhCp*, and Ru(arene) complexes, Cp‡Ru(μ-H)3IrCp* (6b), Cp‡Ru(μ-H)3RhCp* (8), and Cp‡Ru(μ-H)3Ru(arene) (10), were newly synthesized by this method. The reaction mechanism was discussed based on the hetero-bimetallic chloro-hydride intermediates. Absence of main group hydride reagents was responsible for maintaining the hetero-bimetallic structure during the introduction of the hydride ligand, which lead to selective formation of dinuclear mixed-metal trihydride-bridged complexes.

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