77352-23-9Relevant articles and documents
Reactions of monochloramine with Br2, Br3-, HOBr, and OBr-: Formation of bromochloramines
Gazda, Michael,Margerum, Dale W.
, p. 118 - 123 (2008/10/08)
Pulsed-accelerated-flow and stopped-flow spectroscopies are used to measure rate constants for the reactions of NH2Cl with Br2, Br3-, HOBr, and OBr-: NH2Cl + Br2 →kBr2 NHBrCl + Br- + H+; NH2Cl + Br3- →kBr3 NHBrCl + 2Br- + H+; NH2Cl + HOBr →kHOBr NHBrCl + H2O; NH2Cl + OBr- →kOBr NHBrCl + OH-. Rate constants (25.0 °C) are kBr2 = (4.18 ± 0.05) × 108 M-1 s-1, kBr3 = (3.07 ± 0.24) × 107 M-1 s-1, kHOBr = (2.86 ± 0.06) × 105 M-1 s-1, and kOBr = (2.20 ± 0.06) × 104 M-1 s-1. In each reaction, nucleophilic attack of the nitrogen lone electron pair facilitates a Br+ transfer from the bromine species to form the mixed haloamine NHBrCl, which decomposes slowly relative to its rate of formation. With the bromine species in excess, NBr2Cl forms rapidly and subsequently decays with a half-life of ～5 min at pH 6.2. Aqueous molar absorptivities for NBr2Cl are estimated as 4400 M-1 cm-1 at 242 nm and 550 M-1 cm-1 at 300 nm.
