Quantum Chemical Calculation and Evaluation of Partition Coefficients for Classical and Emerging Environmentally Relevant Organic Compounds

• DOI: 10.1021/acs.est.1c06935
• Publication Date: 2021-12-21T14:50:37Z
• Authors: Tunga Salthammer; Stefan Grimme; Marcel Stahn; Uwe Hohm; Wolf-Ulrich Palm
• Keywords: Quantum chemical; Environmentally Friendly

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 extended CRENSO workflow applied here includes the calculation extensive conformer ensembles with semiempirical methods refinement through density functional theory, taking into account solvation models, especially COSMO-RS, thermostatistical contributions. This approach is particularly advantageous describing large nonrigid molecules. With regard to KOW KHdA, one can refer many experimental data from direct indirect measurement methods, very good matches results our quantum chemical evident. In case KOA values, however, only obtained experimentally determined values. Larger systematic deviations between computed available, nonexperimental quantitative structure-activity relationship literature occur in particular phthalic acid esters organophosphate esters. From a critical analysis this work comparison available data, we conclude that presented composite most powerful so far calculating reliable because all physical contributions conformational free energy considered structure two phases generated independently consistently.