Preparation and Characterization of Zinc(II)-Based Lewis/Brønsted Acidic Deep Eutectic Solvents

Abstract

Lewis/Brønsted acidic deep eutectic solvents (LBDESs) are a recent class of solvents that combine the two types of acidity. In some cases, this synergy leads to enhanced catalytic properties for many reactions and applications. For this reason, it is important to discover more LBDESs. In this work, we prepared and characterized four different zinc(II)-based LBDESs, mixing ZnCl2 and various Brønsted acids: acetic, glycolic, levulinic, and formic acids. Apart from the latter, for which the corresponding DES is not thermally stable, the samples have been characterized in terms of density, viscosity, and conductivity. Notably, as zinc(II) is a diamagnetic metal, all of them are suitable for NMR spectroscopy, for example, for kinetic and mechanistic studies.