Kinetics and mechanism of the multi-step oxidation of ethylenediaminetetraacetate by [Ag(OH)4]- in alkaline media
Date of Original Version
Alkaline solutions of [Ag(OH)4]- oxidise ethylenediaminetetraacetate (edta) in a multistep sequence which produces iminodiacetate (ida), glycinate and glycolate ions, and eventually ammonia, formaldehyde, carbon dioxide and water. The reaction shows changing stoichiometry and product distribution. At [edta]0/[Ag(OH)4-]0 = 1:1, glycinate and ida are produced in similar amounts with detectable ammonia and formaldehyde. When [edta]0/[Ag(OH)4-]0 = 200:1, very little glycinate is produced with no ammonia or formaldehyde detected. The kinetics of the oxidation was studied by the stopped-flow method at high excesses of edta and 25 °C and I = 1.2 mol dm-3. The overall rate is as in equation (i), where the coefficients, obtained by non-linear least-square analysis, are A = kobs = (A + B[OH-])[edta4-]/[OH-] + C[edta4-] (i) 4.38 ± 0.57 s-1, B = 34.8 ± 1.1 dm3 mol-1 s-1 and C = 26.3 ± 2.1. A multi-step electron-transfer mechanism is proposed involving initial C-N bond cleavage at the ethylenediamine group.
Publication Title, e.g., Journal
Journal of the Chemical Society, Dalton Transactions
Sun, Yunfu, Louis J. Kirschenbaum, and Issifou Kouadio. "Kinetics and mechanism of the multi-step oxidation of ethylenediaminetetraacetate by [Ag(OH)4]- in alkaline media." Journal of the Chemical Society, Dalton Transactions 9 (1991). doi: 10.1039/DT9910002311.