Alternative probe for the determination of the hydrogen-bond acidity of ionic liquids and their aqueous solutions

authors	Madeira, PP; Passos, H; Gomes, J; Coutinho, JAP; Freire, MG
nationality	International
journal	PHYSICAL CHEMISTRY CHEMICAL PHYSICS
keywords	SOLVATOCHROMIC COMPARISON METHOD; PYRIDINE-N-OXIDE; BIPHASIC SYSTEMS; EXTENDED SCALE; PI-STAR; SOLVENTS; EXTRACTION; PARAMETERS; BEHAVIOR; POLARITY
abstract	Although highly relevant to a priori select adequate solvents for a given application, the determination of the hydrogen-bond acidity or proton donor ability of aqueous solutions of ionic liquids is a difficult task due to the poor solubility of the commonly used probes in aqueous media. In this work, we demonstrate the applicability of the pyridine-N-oxide probe to determine the hydrogen-bond acidity of both neat ionic liquids and their aqueous solutions, based on C-13 NMR chemical shifts, and the suitability of these values to appraise the ability of ionic liquids to form aqueous two-phase systems.
publisher	ROYAL SOC CHEMISTRY
issn	1463-9076
year published	2017
volume	19
issue	18
beginning page	11011
ending page	11016
digital object identifier (doi)	10.1039/c6cp08210f
web of science category	Chemistry, Physical; Physics, Atomic, Molecular & Chemical
subject category	Chemistry; Physics
unique article identifier	WOS:000401022300005