Related Experiment Video
Updated: Jul 9, 2026

Analysis of Organochlorine Pesticides in a Soil Sample by a Modified QuEChERS Approach Using Ammonium Formate
Published on: January 20, 2023
Effect of ortho-chlorine substitution on the partition behavior of chlorophenols
Christian Niederer1, Kai-Uwe Goss
1Institute of Biogeochemistry and Pollutant Dynamics, ETH-Zurich, Universitätsstrasse 16, CH-8092 Zurich, Switzerland.
Abstract:
Chlorophenol isomers are known to possess substantially different octanol/water and octane/water partition constants depending on whether the chlorine substituents are in the ortho or meta/para position. Here we show that the same is also true for environmental partition processes such as water/air and humic acid/air partitioning. Quantitative structure property relationships (QSPR) such as those in the widely used EPI-suite or SPARC fail to correctly predict this influence of the substituent position on the compound's partitioning. Only a more sophisticated quantum chemical software, called COSMOtherm, correctly reproduced these effects. Based on this and earlier experiences we conclude that COSMOtherm may be a better tool for screening large sets of chemicals for which no experimental data on their partitioning yet exist.
Related Concept Videos
Directing Effect of Substituents: ortho–para-Directing Groups
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
ortho–para-Directing Deactivators: Halogens
Hydrolysis of Chlorobenzene to Phenol: Dow Process
Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
Acidity and Basicity of Alcohols and Phenols

