Mokshyna O. Critical properties and second virial coefficients of organic compounds and their mixtures. QSPR analysis with the account for the intermolecular interactions

The main purpose of the thesis was to develop a system to predict thermodynamic properties (critical properties, acentric factor, second virial coefficient) of organic compounds and their binary mixtures using QSPR analysis based on the simplex representation of molecular structure. Novel descriptor representations were developed able to account for intermolecular interactions - "quasi-mixture" approach and pair interaction descriptors. The developed QSPR models were validated and proved able to describe and predict investigated thermodynamic properties of individual compounds and their binary mixtures. The causal analysis was performed for molecular parameters that influence the acentric factor. Usage of "quasi-mixture" descriptors proved to decrease a root-mean-square prediction error for critical properties and second virial coefficients of individual compounds. Influential structural and physic-chemical factors were detected. For the first time the second virial cross-coefficients (В12) were successfully modeled and predicted. Temperature dependence curves for В12 were restored from predictions and compared to the initial data. The external validation showed that the obtained models are applicable towards a prediction of new compounds and previously unstudied mixtures.