Additive polarizabilities in ionic liquids

TL;DR

This paper develops a regression-based method to determine atomic polarizabilities in ionic liquids from experimental data, enabling predictions of molecular properties without detailed structural information.

Contribution

It introduces a novel regression analysis approach to estimate atomic polarizabilities in ionic liquids, improving property predictions and comparing results with quantum-chemical calculations.

Findings

Atomic volumes and polarizabilities can be statistically derived from density and refractive index data.

Discrimination of carbon hybridization states enhances prediction accuracy.

Results align well with experimental and quantum-chemical data.

Abstract

An extended Designed regression analysis of experimental data on density and refractive indices of several classes of ionic liquids yielded statistically averaged atomic volumes and polarizabilities of the constituting atoms. These values can be used to predict the molecular volume and polarizability of an unknown ionic liquid as well as its mass density and refractive index. Our approach does not need information on the molecular structure of the ionic liquid, but it turned out that the discrimination of the hybridization state of the carbons improved the overall result. Our results are not only compared to experimental data but also to quantum-chemical calculations. Furthermore, fractional charges of ionic liquid ions and their relation to polarizability are discussed.