Related Experiment Video
Updated: Dec 31, 2025

Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics
Published on: April 17, 2017
Revealing Intermolecular Hydrogen Bonding Structure and Dynamics in a Deep Eutectic Pharmaceutical by Magic-Angle
Sarah K Mann1, Tran N Pham2, Lisa L McQueen3
1Department of Physics , University of Warwick , Coventry CV4 7AL , U.K.
Abstract:
Liquid forms of pharmaceuticals (ionic liquids and deep eutectic solvents) offer a number of potential advantages over solid-state drugs; a key question is the role of intermolecular hydrogen bonding interactions in enabling membrane transport. Characterization is challenging since high sample viscosities, typical of liquid pharmaceutical formulations, hamper the use of conventional solution NMR at ambient temperature. Here, we report the application of magic-angle spinning (MAS) NMR spectroscopy to the deep eutectic pharmaceutical, lidocaine ibuprofen. Using variable temperature MAS NMR, the neat system, at a fixed molar ratio, can be studied over a wide range of temperatures, characterized by changing mobility, using a single experimental setup. Specific intermolecular hydrogen bonding interactions are identified by two-dimensional 1H-1H NOESY and ROESY MAS NMR experiments. Hydrogen-bonding dynamics are quantitatively determined by following the chemical exchange process between the labile protons by means of line-width analysis of variable temperature 1H MAS NMR spectra.
Related Concept Videos
Hydrogen Bonds
Hydrogen Bonds
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
¹H NMR of Labile Protons: Deuterium (²H) Substitution
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...

