Synthetic Routes to Ruthenium(II) Species Containing Carboxylate-Functionalized 2,2′-Bipyridine Ligands

Abstract

Two methods are reported for the incorporation of carboxylate substituents on polypyridyl ligands coord- inated to ruthenium(II) centres. In the first, a precursor complex is synthesized with ethoxycarbonyl groups which are subsequently base-hydrolysed to produce the carboxylate in high yield (–CO₂Et → –CO₂H). In the second method, ruthenyl (Ru^IV =O) species were used to chemically catalyse the electochemical oxidation of methyl substituents on the ligands of a precursor complex to produce the target carboxylate species (–CH₃ → –CO₂H).