Stabilization of biochemically interesting intermediates by metal coordination. VI: Charge transfer in complexes of 1,3-dimethyllumazine with low-valent metals

Chelate complexes between O(4),N(5)-coordinating 1,3-dimethyllumazine and the metal fragments (Ph 3 P) 2 Cu + , (bpy) 2 Ru 2+ (bpy=2,2'-bipyridine), and (OC) 3 ClRe have metal-to-ligand charge-transfer absorption bands in the visible region. Cyclic voltammetry illustrates the thermodynamic and kinetic stabilization of the reduced state in these complexes