Single-descriptor based quantum-chemical QSPRs for physico-chemical properties of polychlorinated-dibenzo-p-dioxins and -dibenzo-furans (PCDD/Fs): Exploring the role of electron-correlation

Abstract

In this work, we propose and analyze single-descriptor based quantitative structure–property relationships (QSPRs) developed using quantum-chemical descriptors and their electron-correlation contribution, for various physico-chemical properties, namely, aqueous solubility, subcooled liquid vapour pressure, n-octanol/water and n-octanol/air partition coefficients of polychlorinated-dibenzo-p-dioxins (PCDDs) and -dibenzo-furans (PCDFs). The predictivity of the developed QSPRs is examined through external validation procedures employing an external prediction set of chemicals not used in the QSPR model development. From the comparison of different models, it is observed that the total energy and the mean polarizability of a molecule are highly significant in determining the predictivity of a QSPR, whereas dipole moment is found to be a poor descriptor in the models developed for all the properties analyzed. Besides these, the electron density based descriptors, namely, absolute electronegativity and electrophilicity index, were also observed to be highly influential in determining the external prediction for partition coefficients.