Kinetics of oxidation of quinol and ascorbic acid with the phen substituted semiquinone ligand, (5,6-dioxolene-1,10-phenanthroline-O,O), bound to the RuII(bipy)2 moiety

The phen substituted semiquinone ligand, 5,6-dioxolene-1,10-phenanthroline-O,O (sqphen), while bound to the RuII(bpy)2 moeity, oxidizes ascorbic acid and quinol at a slower rate than does the semiquinone (sq) bound to the same moiety; the basicity of sqphen decreases considerably on coordination to RuII(bpy)2, moreover, bound sqphen is less basic than bound sq, but the basicity of bound sqphen enhances on reduction to its catechol form, catphen.