Ground- and excited-state electron-transfer reactions: photoinduced redox reactions of poly(pyridine)ruthenium(II) complexes and cobalt(III) cage compounds

Journal Article · Wed Aug 29 00:00:00 EDT 1984 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00186a035· OSTI ID:6507318

Mok, C Y; Zanella, A W; Creutz, C; Sutin, N

Rate constants for the quenching of poly(pyridine)ruthenium(II) (RuL/sub 3//sup 2 +/) excited states by caged cobalt(III) amine complexes (Co(cage)/sup 3 +/) range from 2 x 10/sup 8/ to 1 x 10/sup 9/ M/sup -1/ s/sup -1/ at 25/sup 0/C. The quenching process involves parallel energy transfer (k/sub en/ approx. 1 x 10/sup 8/ M/sup -1/ s/sup -1/) and electron transfer (k/sub el/ = (0.1-1) x 10/sup 9/ M/sup -1/ s/sup -1/) from RuL/sub 3//sup 2 +/ to Co(cage)/sup 3 +/. The rate constants for electron-transfer quenching are consistent with expectations based on an adiabatic semiclassical model. The yields of electron-transfer products range from 0.3 to 1.0, increasing as the rate constants for the back-reaction of RuL/sub 3//sup 3 +/ with Co(cage)/sup 2 +/ diminish. The relatively low magnitudes of the back-reaction rate constants, (0.08-8) x 10/sup 8/ M/sup -1/ s/sup -1/, are consistent with the high yields of electron-transfer products and derive from poor coupling of the RuL/sub 3//sup 3 +/ and Co(cage)/sup 2 +/ orbitals. 30 references, 3 figures, 4 tables.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 6507318
• Journal Information: Inorg. Chem.; (United States), Vol. 23:18
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COBALT COMPLEXES
CHEMICAL REACTION KINETICS
REDOX REACTIONS
RUTHENIUM COMPLEXES
AMINES
CORRELATIONS
DATA ANALYSIS
ELECTRON TRANSFER
EXCITED STATES
EXPERIMENTAL DATA
GROUND STATES
MATHEMATICAL MODELS
PHOTOLYSIS
PYRIDINES
AZINES
CHEMICAL REACTIONS
COMPLEXES
DATA
DECOMPOSITION
ENERGY LEVELS
HETEROCYCLIC COMPOUNDS
INFORMATION
KINETICS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
REACTION KINETICS
TRANSITION ELEMENT COMPLEXES
400500* - Photochemistry