Kinetics and mechanism of aquation of cobalt(II) - Glycine complexes in aqueous solutions: A pulse radiolytic study

Journal Article · Wed Sep 19 00:00:00 EDT 1990 · Inorganic Chemistry; (USA)

DOI:https://doi.org/10.1021/ic00344a032· OSTI ID:6010332

Shinohara, Nobuyoshi ^[1]; Lilie, J ^[2]

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1. Yokohama City Univ. (Japan)
2. Hahn-Meitner-Institut Berlin GmBH (West Germany)

The kinetics of aquation of tris(glycinato)cobaltate(II), (Co(gly){sub 3}){sup {minus}}, formed by the reaction of the corresponding Co(III) complex with hydrated electrons, has been investigated by conductometric pulse radiolysis in aqueous solutions. The rate of the reactions leading to the loss of each of the three glycinate ions in (Co(gly){sub 3}){sup {minus}} were well separated from each other and were studied as a function of pH. The observed rate constants are given by k{sup 0} + k{sup H}(H{sup +}). For the glycinate ion dissociation from the Co(II) complexes with one, two, and three glycinate ions, k{sup 0} were 4.9 {times} 10, 3.5 {times} 10{sup 2}, and 4.2 {times} 10{sup 3} s{sup {minus}1}, respectively and k{sup H} were 2.1 {times} 10{sup 4}, 8.1 {times} 10{sup 5}, and 2.7 {times} 10{sup 7} M{sup {minus}1} s{sup {minus}1}, respectively. The kinetics and mechanism of the aquation reaction of (Co(gly){sub 3}){sup {minus}} are discussed and compared to those for the aquation of (Co(en){sub 3}){sup 2+} and (Co(acac){sub 3}){sup {minus}}. 26 refs., 4 figs., 1 tab.

• OSTI ID: 6010332
• Journal Information: Inorganic Chemistry; (USA), Journal Name: Inorganic Chemistry; (USA) Vol. 29:19; ISSN 0020-1669; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400600* -- Radiation Chemistry
AMINO ACIDS
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
COBALT COMPLEXES
COMPLEXES
DATA
DECOMPOSITION
EXPERIMENTAL DATA
GLYCINE
INFORMATION
IRRADIATION
KINETICS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
PULSED IRRADIATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
REACTION KINETICS
TRANSITION ELEMENT COMPLEXES