"Development of Ruthenium Vinylbipyridine Modified Electrode Surfaces f" by Matthew F. Piescinski

Degree Name

Master of Science (MS)

Semester of Degree Completion

1991

Thesis Director

Mark E. McGuire

Abstract

Based upon the chemiluminescent properties of [Ru(bpy)3]2+ and the proven analytical applications of that complex in the detection of easily reduced anions in solution, a chromatographic detection system was designed utilizing an immobilized form of the Ru(ll) complex. The objective was to create, by electropolymerization, a regenerative chemiluminescent surface on a working electrode. Reductive electropolymerization was accomplished by the use of a [Ru(bpy)3]2+ analog containing the ligand vinylbipyridine. Two analogs, [Ru(vbpy)3][PF6]2 and [Ru(phen)2(vbpy)][PF6]2 were polymerized on platinum, glassy carbon and indium-doped tin oxide working electrodes and evaluated for chemiluminescent emission in an electrochemical cell using oxalate ion. When held at an oxidative potential slightly above the +3/+2 couple of the complex, no chemiluminescence was observed from oxalate at the surface of either polymer. Pulsing the electrode/polymer surface between the potentials known for the +3 and +1 states also did not yield chemiluminescence. A spectral comparison of equivalent solutions of [Ru(vbpy)3][PF6]2 and [Ru(bpy)3][Cl2] indicated significant differences between the spectra of the oxidized form of each solution. The oxidized form of [Ru(vbpy)3][PF6]2 also demonstrated a more rapid reduction to the +2 state in solution than did the oxidized form of [Ru(bpy)3][Cl2]. Significant luminescence intensity differences were also observed between the fluorescence spectra of [Ru(vbpy)3][PF6]2 and [Ru(bpy)3][Cl2]. These properties may prevent the excited state *[Ru(vbpy)3]2+ complex from deactivating via a chemiluminescence pathway. One possible solution to this problem would be to use a monovinyl ruthenium complex such as [Ru(bpy)2(vbpy)][Cl2] with increased [Ru(bpy)3]2+ character.

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