The QSPR Studies of [SO4 (H2O)n]2−, n = 1-4, 16 Clusters through Quantum-Chemical Descriptors

Abstract

The quantitative structure property relationship (QSPR) is a powerful analytical approach that can link physicochemical properties of the molecular or ionic specimens mathematically with their 3D structures. The primary strategy of this predictive molecular based approach is to obtain optimum quantitative structure-property correlations by employing specific quantum-chemical descriptors (QCDs) that can encode structural features numerically. This theoretical insight is mainly aimed at computing HOMO and LUMO Eigen values and the associated QCDs such as HOMO-LUMO energy gap ( ), Ionization potential ( IP ), Electron affinity ( EA ), Electronegativity ( c ), Chemical hardness ( h ), Chemical softness ( s ), Electronic chemical potentials ( m ), and Electrophilicity index ( ω ) for the variably sized hydrated sulfate clusters [SO 4 (H 2 O) n ] 2− , n = 1-4, & 16 separately using DFT:B3LYP hybrid functional, and predicting their most significant physical properties plus kinetic stabilities quantum mechanically. The major structure-based physical properties assessed here are electronic localization & polarizability, electronegativity, electrophilicity, degree of chemical hardness & softness, and the extent of global electron density transfer. The general results show that [SO 4 (H 2 O) 4 ] 2− has more propensity to loose electrons among the ions with hydration number n < 4, and [SO 4 (H 2 O) 16 ] 2− is the most kinetically instable ion having significant electronic polarizability among other smaller clusters sampled in this study. It is believed that this QCD based QSPR studies for the biologically most important and abundant micronutrient SO 4 2 − ions would be highly useful to understand their physiological roles.