Oxidobridged

Oxidobridged refers to metal complexes in which two or more metal centers are linked by a bridging oxide ligand, commonly described as a μ-oxido or μ-oxo bridge. In these species, an oxide ion coordinates to multiple metal ions, creating a M–O–M core. This motif is widespread in high-valent transition metal chemistry and in metal-oxygen clusters, including dinuclear and polynuclear complexes of iron, manganese, ruthenium, and other metals.

Structural characteristics include short M–O bonds, typically around 1.8–2.1 Å depending on the metals involved, and variable M–O–M angles that can range broadly, often enabling electronic communication between the metal centers. The oxidation states across the metals may be mixed, with the oxide formally carrying a 2− charge and serving as a bridge for redox activity and magnetic exchange.

Formation and relevance: Oxidobridged cores can form by oxidation of hydroxo-bridged precursors, hydrolysis of oxo precursors, or direct incorporation of oxide under oxidative conditions. They are important intermediates in catalytic cycles, including oxidation reactions, O-atom transfer, and water oxidation processes. In bioinorganic chemistry, μ-oxido bridges model structural motifs found in enzyme active sites and in metal-oxide materials.

Distinction: The term emphasizes the bridging oxide as a functional connector between metal centers and is distinct from other μ-bridges such as hydroxo, alkoxo, or carboxylato ligands, though complexes may exhibit mixed bridging modes.