MONOBROMAMINES IN AQUEOUS-MEDIA .1. REACTIVITY TOWARDS AMMONIA, AMINES AND HYDRAZINES

The reactivity of NH2Br in aqueous medium with ammonia, amine and hydrazine was studied at 20,8-degrees-C, in the pH range from 8,0 to 14,6. At pH>12, the kinetic for NH2Br + RNH2 (R=H, CH3) reactions results from the superposition of spontaneous decomposition of monobromamine, formation of hydrazine (slow reaction) ant its fast oxydation. The hydrazine oxydation by monohaloamine is directly dependant on the halogen electronegativity. At pH<12, bromine transfert reaction between monobromamine and the amine was observed, which leads to the formation of substitued monobromamine. The stability of monobromamine depends on the pH and the concentration of reactants. For a defined concentration of NH2Br, the instability limit reaches a minimun at pH 9 to 10. There is a great analogy in NH2Br and NH2Cl behaviours.