The relation between the bactericidal activities and certain physico-chemical properties of some fluorophenols

Abstract

Abstract The antibacterial activities, as demonstrated by the Rideal-Walker coefficients and viable counts, of mono-, 2,4,5– tri-, 2,3,5,6- tetra- and pentafluorophenol increase with the number of substituent fluorine atoms. The thermodynamic activities (Ferguson values) range from 0·083 to 0·022, and indicate a non-specific physical mode of action. Linear correlations occur between the equitoxic concentrations of the compounds to Escherichia coli (99·9% mortality after 50 min contact) and their molecular weights, number of fluorine substituents and water solubilities. A similar relation exists between the molar concentrations at the Rideal-Walker end points and the oleyl alcohol-water partition coefficients; no correlation occurs between toxicity and the cyclohexane-water partition coefficients. The surface tensions of equitoxic solutions vary between 57·5 and 63·2 mNm−1 (dynes/cm).