Reaction of Nitrogen Chelates with the [Rh(2)](4+) Core: Bis-Chelate Products and Demonstration of Reversible, Chelate-Based Reduction Processes.

The preparations and properties are described of a series of [Rh(2)](4+) complexes possessing carboxylates and N-based chelates as ligands. Treatment of Rh(2)(O(2)CR)(4)(MeOH)(2) (R = Me (1), Et (2), Ph (3) or CF(3) (4)) with 2 equiv of 2,2'-bipyridine (bpy) in refluxing MeCN leads to the [Rh(2)(O(2)CR)(2)(bpy)(2)](2+) cation (in complexes 5-9). Reaction of 1 with 1,10-phenanthroline (phen), 4,4'-dimethyl-2,2'-bipyridine (Me(2)bpy), 4,4'-diphenyl-2,2'-bipyridine (Ph(2)bpy), and 4,7-diphenyl-1,10-phenanthroline (Ph(2)phen) leads to the analogous cations of complexes 10-13.

Reactivity of Cubane-Type [(OC)(3)MFe(3)S(4)(SR)(3)](3-) Clusters (M = Mo, W): Interconversion with Cuboidal [Fe(3)S(4)](0) Clusters and Electron Transfer.

The title clusters, several examples of which have been reported earlier, have been prepared by two different methods and subjected to structural and reactivity studies. The compounds (Et(4)N)(3)[(OC)(3)MFe(3)S(4)(Smes)(3)].MeCN (M = Mo/W) are isomorphous and crystallize in monoclinic space group P2(1)/n with a = 13.