Attempts to modify an electrode with a conducting platinum cluster compound

A conducting platinum cluster compound K 1.64 Pt(C 2 O 4 ) 2 was electrochemically synthesized on a glassy carbon electrode through the electrooxidation of K 2 Pt(C, 2 O 4 ) 2 in an aqueous medium using single potential step and cyclic voltammetry methods. The precursor K 2 Pt(C 2 O 4 ) 2 was prepared by a ligand exchange reaction between C 2 O 4 2− and PtCl 4 2− . During single potential step experiments, the electrolytic current corresponding to the oxidation of K 2 Pt(C 2 O 4 ) 2 increased dramatically after a sharp decrease at the beginning (due to the formation of conducting K 1.64 Pt(C 2 O 4 ) 2 on the surface of the working electrode). Two kinds of mechanism account for the current transients at the different applied potentials. Cyclic voltammetry was conducted with K 1.64 Pt(C 2 O 4 ) 2 on the surface of the working electrode and a steady‐state diffusion current was observed. Since the material grew in a fibrous manner, each conducting fiber which was in contact with the electrode could serve as an ultramicroelectrods. The behavior of the working electrode was thus changed from a plain to an ultramicroelectrode array.