Chemical and electrochemical generation of [Fe(bpy)(2)(S)(2)](2+) (bpy = 2,2 '-bipyridine, S = H2O or CH3CN). A route for synthesis of coordinativelydissymmetrical iron(II) polypyridine complexes and supramolecular structures containing a Fe(bpy)(3)(2+) moiety

A route for the synthesis of coordinatively dissymmetrical iron(II) polypyr idine complexes [Fe(L)(2)L'](2+) (L and L' are two different 2,2'-bipyridin e derivatives) is described. The procedure is based on the use of the precu rsor [Fe(L)(2)(CH3CN)(2)](2+) (L = 2,2'-bipyridine), which can be easily pr epared by electrochemical or chemical reduction of the mu-oxo diaqua diiron (III) complex [Fe2O(bpy)(4)(H2O)(2)](4+) in acidic CH3CN solution. In addit ion, it is shown that this procedure can be applied with success to the syn thesis of covalently linked heterodinuclear complexes containing, for insta nce, Fe(bpy)(3)(2+) and Ru(bpy)(3)(2+) moieties. The electrochemical behavi our of all these new complexes is reported.