Polysulfide ligands polynuclear

There are large numbers of compounds with the simple sulfide ion (S2 ) as a ligand comparable to O2- that are mononuclear like S=WC13 or bi- or polynuclear with sulfur bridges. These and related species derived from polysulfide ions (S2 ) have been intensively studied in part because sulfur bridged species occur in Nature in ferredoxins and related compounds. 

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