Determination of Binding Strengths of Host‐Guest Complexes in Deep Eutectic Solvents Using Spin Probe Methodology. Issue 6 (11th February 2021)

• Record Type: Journal Article
• Authors: Cantelli, Andrea; Franchi, Paola; Mezzina, Elisabetta; Lucarini, Marco
• Is Part Of: Chemphyschem. Volume 22:Issue 6(2021)
• Page Start: 517
• Page End: 521
• Publication Date: 2021-02-11
• Subjects: Cyclodextrins -- deep eutectic solvents -- electron paramagnetic resonance -- host-guest chemistry -- spin probes; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.202001007
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Electron paramagnetic resonance (EPR) and spin probe methodologies have been employed to study the complexation properties of cyclodextrins (CDs) and cucurbit[n]urils (CB[n]s) in the deep eutectic solvent (DES) choline chloride‐urea. In the presence of γ‐CD an affinity constant very similar to that measured in water was measured in DES with benzyl‐ tert‐ butyl nitroxide (BTBN). With β‐CD, complexation of BTBN is significantly depressed, although still maintained. Complexation of TEMPO radical probe by CB[7] or CB[8] was instead almost entirely cancelled in DES. In addition, this methodology enabled for the first time to measure the single rate constants for the association and dissociation processes with CDs in DES. Abstract : Host‐guest complexes between cyclodextrins, cucurbit[n]urils, and nitroxide spin probes are investigated in a choline chloride‐urea mixture (DES) by electron paramagnetic resonance techniques.