Reactions of low-valent transition-metal complexes with hydrogen peroxide. Are they Fenton-like or not. 1. The case of Cu/sup +//sub aq/ and Cr/sup 2 +//sub aq/

Journal Article · Wed Jun 22 04:00:00 EDT 1988 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00221a031· OSTI ID:6254549

Masarwa, M; Cohen, H; Meyerstein, D; Hickman, D L; Bakac, A; Espenson, J H

A thermodynamic analysis of the Fenton reaction and the Fenton-like reactions points out that their detailed mechanisms involve the formation of a transient complex between the low-valent cation ML/sub m//sup n/ and hydrogen peroxide of the type ML/sub m-1//sup n//times/O/sub 2/H/sup /minus//. This complex might decompose into ML/sub m//sup n+1/ + /center dot/OH or ML/sub m//sup n+2/ + H/sub 2/O react directly with a substrate. Experimental data from studies in acidified solutions indicate that (H/sub 2/O)/sub 5/Cr/sup 2 +//times/O/sub 2/H/sup -/ decomposes into Cr(H/sub 2/O)/sub 6//sup 3 +/ + /center dot/OH in the presence of greater than or equal to 0.1 mM ethanol, 2-propanol, and 2-butanol, whereas (H/sub 2/O)/sub m/Cu/sup +//center dot/O/sub 2/H/sup -/ reacts with the alcohols directly. However, in the absence of an organic substrate, the latter complex in acidic solution decomposes into Cu(H/sub 2/O)/sub n//sup 2 +/ + /center dot/OH. The specific overall reactions rates of Cu/sup +//sub aq/ with H/sub 2/O/sub 2/, (CH/sub 3/)/sub 3/COOH, and S/sub 2/O/sub 8//sup 2/minus// are 4.1 /times/ 10/sup 3/, /approximately/ 4 /times/ 10/sup 3/, and greater than or equal to 1 /times/ 10/sup 7/ M/sup /minus/1/ s/sup /minus/1/, respectively.

• Research Organization: Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel)
• OSTI ID: 6254549
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 110:13; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AQUEOUS SOLUTIONS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHROMIUM COMPLEXES
COMPLEXES
COPPER COMPLEXES
DATA
DISPERSIONS
EXPERIMENTAL DATA
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
INFORMATION
KINETICS
MIXTURES
NUMERICAL DATA
OXYGEN COMPOUNDS
PEROXIDES
PH VALUE
REACTION KINETICS
SOLUTIONS
THERMODYNAMICS
TRANSITION ELEMENT COMPLEXES
VALENCE