Metal complexes as mediator-titrants for electrochemical studies of biological systems.

Various redox-active metal complexes were evaluated electrochemically for stability, reversibility, and general utility as mediator-titrants in the 0 to + 1.0 V vs standard hydrogen electrode range. Those complexes which were evaluated and appear to be useful in potentiostatic or potentiometric techniques are Ru(bpy)3(CIO4)2, Ru(bpy)2(im)2, Os(bpy)3(NO3)2, K2Fe(phen)(CN)4, Co(phen)3Cl2, and Co(terpy)2Cl2.