A diazene-bridged diruthenium complex with structural restraint defined by single meta-diphosphinobenzene

Abstract

Creation of confined coordination spaces with controlled flexibility is of importance in mimicking enzymatic reactions. We found that a simple, non-chelating 1,3-bis(diphenylphosphino)benzene (DPPBz) assembled two Cp*Ru units to give a dinuclear complex, wherein only one DPPBz supports an open framework without metal–metal bonding. Subsequent treatment with an excess of hydrazine resulted in formal 2e⁻/2H⁺ transfer from hydrazine to afford a diazene-bridged complex featuring intramolecular NH⋯Cl hydrogen bonds. In constrast, a monophosphine failed to stabilize the diazene-bridged dinuclear structure due to the lack of the enforcement of the conformation.