Determination of tris(2,2'-bipyridyl)ruthenium(II) derivatives by reverse phase paired-ion high performance liquid chromatography

Reverse-phase paired-ion high performance liquid chromatography (HPLC) has been used to determine diester, monoester-monocarboxylate and dicarboxylate derivatives of tris(2,2'-bipyridyl)ruthenium(II) (Ru/sup II/(bpy)/sub 3//sup 2 +/) which can be distinguished on the basis of water solubility and molecular charge. Positively charged surfactant ruthenium derivatives have been ion-paired with methanesulfonate anions in the aqueous tetrahydrofuran mobile phase while their water soluble analogues have been paired with n-heptanesulfonate anions to provide suitable retention for separation on a C/sub 18/ bonded column. Using optical detection at 280 nm, the lower limit of sensitivity is 1 x 10/sup -12/ mol with +-2% precision at the 2.5 x 10/sup -9/ mol level. Monitoring hydrolysis reactions of diester derivatives of Ru/sup II/(bpy)/sub 3//sup 2 +/ by HPLC has proven superior to absorption and emission spectrometry.