Transients in the flash photolysis of aqueous solutions of tris(2,2'-bipyridine)ruthenium(II) ion

Journal Article · Thu Jul 28 04:00:00 EDT 1977 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100530a004· OSTI ID:7316829

Meisel, D; Matheson, M S; Mulac, W A; Rabani, J

Aqueous solutions of Ru(bpy)/sub 3//sup 2 +/ (bpy = 2,2'-bipyridine) were flash photolyzed and pulse irradiated in the presence and in the absence of other additives. Hydrated electrons are produced in a process which is suggested to involve electron ejection from the first triplet of Ru(bpy)/sub 3//sup 2 +/, upon the absorption of a second photon. Most of the effective light (approximately 70%) was in the range 300 to 340 nm, while approximately 30% of the effective light was at wavelength >340 nm. The efficiency of e/sub aq/ production relative to the efficiency of production of the lowest triplet charge transfer state was measured under our conditions as 0.0015, independent of (Ru(bpy)/sub 3//sup 2 +/) and of flash intensity over a wide range. During our work on the biphotonic process for e/sup -//sub aq/ formation, a number of other reactions were investigated. Thus, hydrated electrons react with Ru(bpy)/sub 3//sup 2 +/ with a reaction rate constant of (5.8 +- 0.3) x 10/sup 10/ M/sup -1/s/sup -1/. The metal ions Zn/sup +/, Co/sup +/, and Cd/sup +/ reduce (Ru(bpy)/sub 3//sup 2 +/ with reaction rate constants (1.5 +- 0.2) x 10/sup 9/, (1.7 +- 0.2) x 10/sup 9/, and (6.1 +- 0.6) x 10/sup 8/ M/sup -1/ s/sup -1/, respectively, producing Ru(bpy)/sub 3//sup +/. Ru(bpy)/sub 3//sup +/ reacts with O/sub 2/, Cu/sup 2 +/, and duroquinone; the reaction rate constants are (7.2 +- 0.8) x 10/sup 9/, (3.4 +- 0.3) x 10/sup 8/, and (4.0 +- 0.5) x 10/sup 9/ M/sup -1/ s/sup -1/, respectively. The possibility for a biphotonic effect leading to H/sub 2/ formation is discussed.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 7316829
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 81:15; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400500 -- Photochemistry
400600* -- Radiation Chemistry
ADDITIVES
AQUEOUS SOLUTIONS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DECOMPOSITION
DISPERSIONS
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
IRRADIATION
LEPTONS
MIXTURES
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PULSED IRRADIATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
RUTHENIUM COMPLEXES
SOLUTIONS
SOLVATED ELECTRONS
TRANSITION ELEMENT COMPLEXES