Quantum chemical calculation of partition coefficients for environmentally relevant organic compounds

In order to reliably estimate the distribution of a chemical substance between the gas phase, particle phase and house dust, partitioning coefficients that are as accurate as possible are required. Here, the octanol/water (KOW), octanol/air (KOA) and hexadecane/air (KHdA) partition coefficients are calculated for 67 organic compounds of environmental concern using computational chemistry. The applied extended CRENSO workflow includes the calculation of extensive conformer ensembles with semiempirical methods and refinement through density functional theory (DFT) taking into account solvation models and thermostatistical contributions. This approach is particularly advantageous for describing large and non-rigid molecules. From a critical analysis of the coefficients determined in this work and comparison with available literature data, we conclude that the presented quantum chemical method is the most powerful so far for calculating reliable partition coefficients.