Photochemistry of compounds adsorbed into cellulose. 1. Decay of excited tris(2,2'-bipyridine)ruthenium(II)

Journal Article · Thu Feb 17 00:00:00 EST 1983 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100227a019· OSTI ID:5749251

Milosavljevic, B H; Thomas, J K

Tris(2,2'-bipyridine)ruthenium(II), Ru(bpy)/sub 3//sup 2 +/, was adsorbed into a cellulose film and the excited-triplet-state decay was studied at 77 and 295 K by using laser photolysis techniques. The triplet (denoted as *Ru(II)) decay depends on both Ru(bpy)/sub 3//sup 2 +/ concentration and laser pulse intensity and follows the equation -(d(*Ru(II))/dt) = k/sub 1/(*Ru(II)) + k/sub 2/(*Ru(II))(Ru(II)) + k/sub 3/(*Ru(II))/sup 2/. At room temperature the rate constant k/sub 1/, which corresponds to the inherent unimolecular decay, is (8.8 +/- 0.5) x 10/sup 5/ s/sup -1/, k/sub 2/ = (7.8 +/- 0.8) x 10/sup 6/ mol/sup -1/ dm/sup 3/ s/sup -1/ and corresponds to quenching by Ru(bpy)/sub 3//sup 2 +/ ground state, and k/sub 3/ = (5.2 +/- 0.6) x 10/sup 7/ mol/sup -1/ dm/sup 3/ s/sup -1/ and corresponds to triplet-triplet annihilation which is followed by electron transfer. Charge separation arising from the quenching process is found to be small. In order to facilitate the interpretation of the above processes, similar experiments were accomplished in water and water-glycerol mixtures. The rate constants, obtained in aqueous solutions, for Ru(bpy)/sub 3//sup 2 +/ ground-state quenching and triplet-triplet annihilation are (5.1 +/- 0.6) x 10/sup 7/ and (1.1 +/- 0.3) x 10/sup 8/ mol/sup -1/ dm/sup 3/ s/sup -1/, respectively; details of the reaction mechanism are also given.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 5749251
• Journal Information: J. Phys. Chem.; (United States), Vol. 87:4
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
RUTHENIUM COMPLEXES
ADSORPTION
PHOTOCHEMISTRY
ANNIHILATION
AQUEOUS SOLUTIONS
CELLULOSE
ELECTRON TRANSFER
EXCITED STATES
LASER RADIATION
PHOTOLYSIS
PYRIDINE
QUENCHING
AZINES
BASIC INTERACTIONS
CARBOHYDRATES
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DECOMPOSITION
DISPERSIONS
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
HETEROCYCLIC COMPOUNDS
INTERACTIONS
MIXTURES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
POLYSACCHARIDES
PYRIDINES
RADIATIONS
SACCHARIDES
SOLUTIONS
SORPTION
TRANSITION ELEMENT COMPLEXES
400500* - Photochemistry