Non-Ideality in Thymol plus Menthol Type V Deep Eutectic Solvents

authors	Schaeffer, N; Abranches, DO; Silva, LP; Martins, MAR; Carvalho, PJ; Russina, O; Triolo, A; Paccou, L; Guinet, Y; Hedoux, A; Coutinho, JAP
nationality	International
journal	ACS SUSTAINABLE CHEMISTRY & ENGINEERING
author keywords	Alternative solvent; Characterization; Hydrogen-bonding; Temperature dependent; Nonionic eutectic solvent
abstract	The nonionic Type V deep eutectic solvent (DESs) thymol + menthol is experimentally and computationally studied aiming to clarify the relation between its liquid phase structure and its thermodynamic nonideality. H-1 NMR, Raman, and X-ray scattering analysis of the thymol + menthol system, supported by molecular dynamics simulations, show complex intermolecular interactions dominated by sterically hindered H-bonded clusters. For temperatures greater than or equal to room temperature, a quasi-linear evolution of the eutectic system properties between the pure compounds is observed, suggesting the absence of a magic stoichiometric composition in the eutectic solvent. However, temperature dependent Raman spectroscopy indicates a notable increase in thymol-menthol H-bonding as temperatures approach the eutectic point. This study shows that nonionic Type V DESs present an important temperature-dependent nonideality originating from the change in the intermolecular H-bonding with temperature. These findings have significant implications for the design and growing application of Type V DESs.
publisher	AMER CHEMICAL SOC
issn	2168-0485
year published	2021
volume	9
issue	5
beginning page	2203
ending page	2211
digital object identifier (doi)	10.1021/acssuschemeng.0c07874
web of science category	9
subject category	Chemistry, Multidisciplinary; Green & Sustainable Science & Technology; Engineering, Chemical
unique article identifier	WOS:000618670600021