Molecular motions in supercooled and glassy ibuprofen: deuteron magnetic resonance and high-resolution rheology study.

Abstract

Using deuteron nuclear magnetic resonance, the molecular motions of specifically isotope-labeled ibuprofen were probed at the carboxylic group and at the methin group next to it. Spin relaxometry revealed slight differences between the molecular motions of the two isotopomers that are rationalized with reference to the hydrogen bonding of the COOH moiety. In the glassy state, a small-angle jump process among about four sites, related to the so-called γ-process, was identified using stimulated-echo spectroscopy. Indications for a Debye-like process, previously found to leave a weak signature in the dielectric loss, could not unambiguously be detected in magnetic resonance or shear mechanical experiments carried out for supercooled liquid ibuprofen.

DOI: 10.1021/acs.jpcb.5b01072

Cite this paper

@article{Bauer2015MolecularMI, title={Molecular motions in supercooled and glassy ibuprofen: deuteron magnetic resonance and high-resolution rheology study.}, author={Stefan Bauer and Michael Storek and Catalin P Gainaru and Herbert Zimmermann and Roland B{\"{o}hmer}, journal={The journal of physical chemistry. B}, year={2015}, volume={119 15}, pages={5087-95} }