TY - JOUR
T1 - Molecular motions in supercooled and glassy ibuprofen
T2 - Deuteron magnetic resonance and high-resolution rheology study
AU - Bauer, S.
AU - Storek, M.
AU - Gainaru, C.
AU - Zimmermann, H.
AU - Böhmer, R.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/4/16
Y1 - 2015/4/16
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=84927947085&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcb.5b01072
DO - 10.1021/acs.jpcb.5b01072
M3 - Article
C2 - 25785657
AN - SCOPUS:84927947085
SN - 1520-6106
VL - 119
SP - 5087
EP - 5095
JO - Journal of Physical Chemistry B
JF - Journal of Physical Chemistry B
IS - 15
ER -