Radiolytic study of the reactions of hydroxyl radical with cobalt(III), iron(II), and ruthenium(II) complexes containing 2,2 prime -bipyridyl and cyano ligands

Journal Article · Wed Jan 24 04:00:00 EST 1990 · Inorganic Chemistry; (USA)

DOI:https://doi.org/10.1021/ic00327a037· OSTI ID:6944869

Maliyackel, A C; Waltz, W L; Woods, R J ^[1]; Lilie, J ^[2]

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1. Univ. of Saskatchewan, Saskatoon (Canada)
2. Hahn-Meitner-Institut Berlin GmbH (West Germany)

The reactions of hydroxyl radical with the complex ions (Co(bpy){sub 3}){sup 3+}, (Fe(bpy){sub 3}){sup 2+}, (Fe(bpy){sub 2}(CN){sub 2}), (Fe(bpy)(CN){sub 4}){sup 2{minus}}, (Fe(CN){sub 6}){sup 4{minus}}, (Fe(Me{sub 2}bpy){sub 3}){sup 2+} and with bpy and Hbpy{sup +}, where bpy = 2,2{prime}-bipyridine and Me{sub 2}bpy = 4,4{prime}-di-methyl-2,2{prime}-bipyridine, have been investigated in N{sub 2}O-saturated aqueous media. The results from tie-resolved studies, carried out by using pulse radiolysis in conjunction with conductivity and near-UV-visible optical detection methods, show that the OH reactions occur with rate constants in the range (2-17) {times} 10{sup 9} M{sup {minus}1} s{sup {minus}1}. For the reactions of bpy and the tris(bipyridyl) complex ions, the absence of significant conductivity movements accompanying the initial optical changes demonstrates that the processes are ones involving OH addition to the systems. The products are reactive toward hexacyanoiron(III) and molecular oxygen, and the associated findings clearly implicate these species to be of a ligand-radical type; however, the evidence also indicates in several cases the occurrence of more than one initially observed product. The reaction of ferrocyanide involves electron transfer whereas for the mixed cyano-bipyridyl complexes of iron(II) both electron-transfer and OH-addition processes are encountered, and the predominant process for (Fe(bpy)(CN){sub 4}){sup 2{minus}} proceeds by an inner-sphere electron-transfer mechanism. Determinations for some of the final products arising from the pulse and {gamma}-ray radiolysis of the mixed cyano-bipyridyl complexes, (Co(gpy){sub 3}){sup 3+}, and (Fe(bpy){sub 3}){sup 2+} have been undertaken in order to obtain insight into the overall sequence of events, and the natures of the mechanisms are discussed. 61 refs., 3 figs., 3 tabs.

• OSTI ID: 6944869
• Journal Information: Inorganic Chemistry; (USA), Journal Name: Inorganic Chemistry; (USA) Vol. 29:2; ISSN 0020-1669; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
AQUEOUS SOLUTIONS
AZINES
BIPYRIDINES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
COBALT COMPLEXES
COMPLEXES
CYANIDES
DATA
DECOMPOSITION
DISPERSIONS
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
GAMMA RADIATION
HETEROCYCLIC COMPOUNDS
INFORMATION
IONIZING RADIATIONS
IRON COMPLEXES
IRRADIATION
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PULSED IRRADIATION
PYRIDINES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADIOLYSIS
RUTHENIUM COMPLEXES
SOLUTIONS
TRANSITION ELEMENT COMPLEXES