| Abstract
| - Monochloramine reacts with hydrated electrons very rapidly, k(NH2Cl+eaq-) = (2.2 ± 0.3) × 1010 L mol-1s-1, to produce •NH2 radicals. It reacts with •OH radicals more slowly, k(NH2Cl+•OH) = (5.2 ± 0.6) × 108L mol-1 s-1, to produce •NHCl radicals. While •NH2 exhibits an absorption peak at 530 nm, with a molarabsorption coefficient ε530 = 80 L mol-1 cm-1, •NHCl exhibits two peaks at 330 and 580 nm, ε330 = (85 ±30) L mol-1 cm-1 and ε580 = (56 ± 30) L mol-1 cm-1. The •NHCl radical undergoes self-decay and can reactalso with O2 to form a peroxyl radical. It is suggested that the peroxyl radical exists in equilibrium NHClO2•⇆ •NHCl + O2 with an estimated equilibrium constant of (3 ± 2) × 10-3 mol L-1. The reaction of chloraminewith the carbonate radical is suggested to form a complex [CO3NH2Cl]•- with kf = 2.5 × 105 L mol-1 s-1and kr = 4 × 102 s-1, and this complex decomposes with k = 7 × 102 s-1 to form •NHCl.
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