UV and IR Spectral Characteristics of Chloramben in Selected Environments

Abstract

Ultraviolet (UV) absorption spectra were recorded of chloramben (3-amino-2,5-dichlorobenzoic acid) and selected relatives in solutions of different pH's. From these spectra, the Broensted acid-base properties of chloramben were deduced. Interpretations of solution spectra were applied to UV absorption spectra of chloramben adsorbed onto Ca-montmorillonite at low water content. Infrared (IR) transmittance spectra were recorded of chloramben and selected derivatives in KBr pellets and band assignments were made. Interpretations of these spectra were also applied to IR spectra of chloramben adsorbed onto Ca-montmorillonite at low water content. Both UV and IR measurements indicated that protonation of the amino group occurs and that the carboxyl group of chloramben is strongly hydrogen-bonded to the hydration water of the interlayer cations.