Electrochemistry and photocurrents of the tris(bipyridine)ruthenium(II) and methyl viologen cations immobilized in carrageenan hydrogel. [tris(2,2'-bipyridine)ruthenium(II)]

Journal Article · Wed Nov 13 04:00:00 EST 1991 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00023a026· OSTI ID:7163301

Rillema, D P; Edwards, A K ^[1]; Perine, S C; Crumbliss, A L ^[2]

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1. Univ., of North Carolina, Charlotte (United States)
2. Duke Univ., Durham, NC (United States)

A procedure for immobilization of both a photochromophore, tris(2,2{prime}-bipyridine)ruthenium(II) (Ru(bpy){sub 3}{sup 2+}), and a quencher, methyl viologen (MV{sup 2+}), within a carrageenan hydrogel matrix at an electrode surface is described. Ru(bpy){sub 3}{sup 2+} and MV{sup 2+} exhibited diffusion coefficients that ranged from 10{sup {minus} 7} to 10{sup {minus} 6} cm{sup 2}/s in the hydrogel, which represents an improvement over other immobilization matrices. Photolysis of the resulting hydrogel surface modified electrodes gave rise to a significant photocurrent which depended on the concentrations of Ru(bpy){sub 3}{sup 2+}, MV{sup 2+}, and triethanolamine and resulted in a maximum value of 12 {mu}A/cm{sup 2} after the hydrogel was cured with a solution containing 5 mM Ru(bpy){sub 3}{sup 2+} and 50 mM MV{sup 2+}. The photocurrent was the result of reoxidation of MV{sup +} at the electrode surface following reduction of MV{sup 2+} by photoexcited Ru(bpy){sub 3}{sup 2+}. The quenching rate constant of Ru(bpy){sub 3}{sup 2+} by MV{sup 2+} in the hydrogel was 4.2 {times} 10{sup 8} M{sup {minus}1} s{sup {minus}1}. The photocurrent action spectrum was consistent with Ru(bpy){sub 3}{sup 2+} acting as the photochromophore. Offsetting the potential of the hydrogel electrode verified the role of the MV{sup 2+}/{sup +} redox couple as the source of the current.

• DOE Contract Number: FG05-84ER13263
• OSTI ID: 7163301
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 30:23; ISSN 0020-1669; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400* -- Electrochemistry
400500 -- Photochemistry
AMINES
AZINES
BIPYRIDINES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
CURRENTS
DECOMPOSITION
ELECTRIC CURRENTS
ELECTROCHEMISTRY
ELECTRODES
EVALUATION
HETEROCYCLIC COMPOUNDS
KINETICS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PHOTOCURRENTS
PHOTOELECTRIC EFFECT
PHOTOELECTROMAGNETIC EFFECTS
PHOTOLYSIS
PYRIDINES
REACTION KINETICS
REDUCTION
RUTHENIUM COMPLEXES
SURFACE PROPERTIES
SYNTHESIS
TRANSITION ELEMENT COMPLEXES