Chlorination of Monochlorodimedone with Chloramines. II. Chlorination Rate Constants for Chlorinated Nitrogenous Compounds.

Abstract

N-Chloro nitrogenous compounds were formed by addition of HOCl to an aqueous solution of ammonia, various amines, imines, amides, imides, and amino acids. The chlorination reactivities of these N-chloro compounds were evaluated with monochlorodimedone (MCD) chlorination rate constants, (kinetics was defined in a previous paper), at pH 7 and at room temperature. The rate constants varied with the structure of the nitrogenous compounds and with the number of chlorine atoms (Cl+) combined with the nitrogen atom in the compound. The rate constants (min-1) for chlorinated secondary amines such as dimethylamine, diethylamine and N-methylglycine (0.338-1.540) were higher than those for monochlorinated primary amines methylamine, ethylamine, and glycine (0.169-0.464). The rate constants for strong base imines like piperazine and morpholine (0.025 and 0.031, respectively) were much lower than those for weak base imines like piperidine and piperazinedione (0.924 and 0.441, respectively). The rate constants for these monochlorinated primary amines (0.123-0.464) were higher than those for dichlorinated primary amines (0.061-0.087). In ammonia chloramines, the rate constant of NH2Cl (0.027) at 12°C was about ten times higher than that of NHCl2 (0.0025) at 12°C.