Prediction of Electrical Conductivity of Deep Eutectic
Solvents Using COSMO-RS Sigma Profiles as Molecular Descriptors: A
Quantitative Structure–Property Relationship Study
posted on 2020-07-07, 15:33authored byTarek Lemaoui, Ahmad S. Darwish, Nour El Houda Hammoudi, Farah Abu Hatab, Ayoub Attoui, Inas M. Alnashef, Yacine Benguerba
This work presents the development
of molecular-based mathematical
models for the prediction of electrical conductivity of deep eutectic
solvents (DESs). Two new quantitative structure–property relationship
(QSPR) models based on conductor-like screening model for real solvent
(COSMO-RS) molecular charge density distributions (Sσ-profiles) were developed using the data obtained
from the literature. The data comprise 236 experimental electrical
conductivity measurements for 21 ammonium- and phosphonium-based DESs,
covering a wide range of temperatures and molar ratios. First, the
hydrogen-bond acceptors (HBAs) and hydrogen-bond donors (HBDs) of
each DES were successfully modeled using COSMO-RS. Then, the calculated Sσ-profiles were used as molecular descriptors.
The relation between the conductivity and the descriptors in both
models has been expressed via multiple linear regression.
The first model accounted for the structure of the HBA, the HBD, the
molar ratio, and temperature, whereas the second model additionally
incorporated the interactions between the molecular descriptors. The
results showed that by accounting for the interactions, the regression
coefficient (R2) of the predictive model
can be increased from 0.801 to 0.985. Additionally, the scope and
reliability of the models were further assessed using the applicability
domain analysis. The findings showed that QSPR models based on Sσ-profiles as molecular descriptors are
excellent at describing the properties of DESs. Accordingly, the obtained
model in this work can be used as a useful guideline in selecting
DESs with the desired electrical conductivity for industrial applications.