Nucleophilic addition of. cap alpha. -hydroxyalkyl radicals to polypyridyl complexes of chromium(III), cobalt(III), rhodium(III), and ruthenium(II) in aqueous solution

Journal Article · Thu Aug 21 04:00:00 EDT 1980 · J. Phys. Chem.; (United States)

OSTI ID:5018406

Venturi, M ^[1]; Emmi, S; Fuochi, P G; Mulazzani, Q G

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1. Instituto di fotochimica e radiazioni d'Alta Energia del C.N.R., Bologna, Italy

The reactions of radiolytically generated ..cap alpha..-hydroxyalkyl radicals of the form R/sub 1/R/sub 2/COH, where R = H and CH/sub 3/ with M(NN)/sub 3//sup n+/ complexes, where M = Cr(III), Co(III), Rh(III), and Ru(II) and NN = 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen), proceed via electron transfer and/or addition of the radicals to the complex. The distribution of the products is controlled by the relative rate constants of electron transfer and addition which, in turn, are affected by the redox potential of the radical-complex couple and by the nature of the ligand. The overall rate constants for the radicals increase always in the order .CH/sub 2/OH < CH/sub 3/CHOH < (CH/sub 3/)/sub 2/COH. The radical adducts show lambda/sub max/ 475 nm and are discussed in terms of the known nucleophilic character of the ..cap alpha..-hydroxyalkyl radicals and the electron-deficient nature of these nitrogen heteroaromatic ligands. The limitations to the utilization of methanol, ethanol, and 2-propanol as H and OH radical scavengers and as sources of reducing radicals in the presence of polypyridyl complexes is discussed.

• OSTI ID: 5018406
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 84:17; ISSN JPCHA
• Country of Publication: United States
• Language: English

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38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
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ALCOHOLS
AQUEOUS SOLUTIONS
AZINES
BIPYRIDINES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
CHROMIUM COMPLEXES
COBALT COMPLEXES
COMPARATIVE EVALUATIONS
COMPLEXES
CONVERSION
DECOMPOSITION
DISPERSIONS
ENERGY CONVERSION
ETHANOL
HETEROCYCLIC COMPOUNDS
HYDROGEN PRODUCTION
HYDROXY COMPOUNDS
METHANOL
MIXTURES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENANTHROLINES
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PROPANOLS
PULSES
PYRIDINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
RHODIUM COMPLEXES
RUTHENIUM COMPLEXES
SOLAR ENERGY CONVERSION
SOLUTIONS
TRANSITION ELEMENT COMPLEXES