Sulfidebridged

Sulfide-bridged refers to a chemical species in which one or more sulfide ligands (S2−) serve as bridges between two or more metal centers. The most common bridging mode is μ2-S, where a single sulfide connects two metals, but μ3-S and μ4-S bridges are also found in multinuclear clusters. Bridging sulfide ligands often sit between late transition metals and can induce short metal–metal contacts and electronic communication across the core.

The presence of μ-S bridges stabilizes multinuclear cores and can modulate redox properties, magnetic coupling, and catalytic activity. Sulfide ligands are soft donors and prefer metals with available d-orbitals; the bridges may adopt various geometries (bent or linear) depending on metal identities and oxidation states.

In inorganic and bioinorganic chemistry, sulfide bridges appear in synthetic metal carbonyl and cluster complexes as well as in iron–sulfur proteins and related clusters. They help mimic natural processes and provide models for electron transfer and catalytic transformations, including reduction and small-molecule activation.

Preparation and characterization typically involve reactions of metal precursors with sulfide sources under appropriate conditions, followed by crystallization for structural determination. Characterization uses X-ray diffraction to locate μ-S bridges, infrared or Raman spectroscopy to detect M–S vibrations, and various magnetic or electrochemical techniques to probe properties.