Water solubility and partitioning behavior of brominated phenols

The water solubility (Sw) in the temperature range from 283 to 308 K and 1-octanol/water partition coefficient (Kow) for the nonionic form of brominated phenols (BPhs) of varying bromine content (4-bromophenol, 2,4-dibromophenol, 2,4,6-tribromophenol, and pentabromophenol) were measured by the generator-column or shake-flask method and by the high-performance liquid chromatography method, respectively. The temperature dependence of Sw, namely enthalpy of solution (deltaHsolution), was calculated using the van't Hoff Equation. To determine the activity coefficients in water (gammaw) of BPhs from the Sw data, enthalpy of fusion (deltaHfusion) and melting point (Tm) were measured by a differential scanning calorimetry method. The gammaw was used for evaluating data consistency as well as for predicting other physico-chemical properties, such as the Henry's law constant (Hw). The present work systematically reports, to our knowledge for the first time, the experimental values of Sw, Kow, deltaHsolution, deltaHfusion, Tm, and gammaw for BPhs with one to five bromines, and it discusses the effects of bromine content on these physico-chemical properties. Finally, the overall physico-chemical characteristics of BPhs are compared with those of polychlorinated phenols, polycyclic aromatic hydrocarbons, and brominated benzenes with the same solubility level as BPhs.