Looking into the Dynamics of Molecular Crystals of Ibuprofen and Terephthalic Acid Using O and H Nuclear Magnetic Resonance Analyses
Overview
Authors
Affiliations
Oxygen-17 and deuterium are two quadrupolar nuclei that are of interest for studying the structure and dynamics of materials by solid-state nuclear magnetic resonance (NMR). Here, O and H NMR analyses of crystalline ibuprofen and terephthalic acid are reported. First, improved O-labelling protocols of these molecules are described using mechanochemistry. Then, dynamics occurring around the carboxylic groups of ibuprofen are studied considering variable temperature O and H NMR data, as well as computational modelling (including molecular dynamics simulations). More specifically, motions related to the concerted double proton jump and the 180° flip of the H-bonded (-COOH) unit in the crystal structure were looked into, and it was found that the merging of the C=O and C-OH O resonances at high temperatures cannot be explained by the sole presence of one of these motions. Lastly, preliminary experiments were performed with a H- O diplexer connected to the probe. Such configurations can allow, among others, H and O NMR spectra to be recorded at different temperatures without needing to tune or to change probe configurations. Overall, this work offers a few leads which could be of use in future studies of other materials using O and H NMR.
O NMR Spectroscopy Reveals CO Speciation and Dynamics in Hydroxide-Based Carbon Capture Materials.
Rhodes B, Schaaf L, Zick M, Pugh S, Hilliard J, Sharma S Chemphyschem. 2024; 26(5):e202400941.
PMID: 39565330 PMC: 11878753. DOI: 10.1002/cphc.202400941.
Nelson A, Papawassiliou W, Paul S, Hediger S, Hung I, Gan Z Faraday Discuss. 2024; 255(0):451-482.
PMID: 39390961 PMC: 11710991. DOI: 10.1039/d4fd00108g.
H/O Chemical Shift Waves in Carboxyl-Bridged Hydrogen Bond Networks in Organic Solids.
Wu G, Dai Y, Hung I, Gan Z, Terskikh V J Phys Chem A. 2024; 128(21):4288-4296.
PMID: 38748612 PMC: 11840671. DOI: 10.1021/acs.jpca.4c01866.
Goldberga I, Patris N, Chen C, Thomassot E, Trebosc J, Hung I J Phys Chem C Nanomater Interfaces. 2022; 126(29):12044-12059.
PMID: 35928237 PMC: 9340807. DOI: 10.1021/acs.jpcc.2c02070.
Hung I, Keeler E, Mao W, Gorkov P, Griffin R, Gan Z J Phys Chem Lett. 2022; 13(28):6549-6558.
PMID: 35830592 PMC: 9888599. DOI: 10.1021/acs.jpclett.2c01777.