𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Local and global dynamics in the glass-forming di-isobutyl phthalate as studied by 1H NMR

✍ Scribed by S. Glowinkowski; S. Jurga; W. Suchanski; E. Szczesniak

Publisher
Elsevier Science
Year
1997
Tongue
English
Weight
458 KB
Volume
7
Category
Article
ISSN
0926-2040

No coin nor oath required. For personal study only.

✦ Synopsis

Spin-lattice relaxation

times T, and T,, as well as 'H NMR spectra have been employed to study the dynamics of the glass-forming di-isobutyl phthalate in the temperature range extending from 100 K, through the glass transition temperature Ts, up to 340 K. Below 2" NMR relaxation is governed by local dynamics and may be attributed to rotation of methyl groups at low temperatures and to motion of isobutyl groups in the intermediate temperature interval. Above Ts the main relaxation mechanism is provided by overall molecular motion. The observed relaxation behavior is explained by motional models assuming asymmetrical distributions of correlation times. The motional parameters obtained from Davidson-Cole distribution, which yields the best fit of the data at all temperatures are given. 0 1997 Elsevier Science B.V.

📜 SIMILAR VOLUMES

Dynamics of glass-forming di-n-butyl pht
Dynamics of glass-forming di-n-butyl phthalate as studied by NMR
✍ E. Szcześniak; S. Głowinkowski; W. Suchański; S. Jurga 📂 Article 📅 1997 🏛 Elsevier Science 🌐 English ⚖ 573 KB

Spin-lattice relaxation times T1 and nuclear Overhauser effect (NOE) enhancement factors for the individual ring carbons in di-n-butyl phthalate (DBF) show that the reorientational correlation function corresponding to the global dynamics in supercooled liquid can be described by a Davidson-Cole dis

γ-Cyclodextrin as Inhibitor of the Preci
γ-Cyclodextrin as Inhibitor of the Precipitation Reaction between Berberine and Glycyrrhizin in Decoctions of Natural Medicines: Interaction Studies of Cyclodextrins with Glycyrrhizin and Glycyrrhetic Acid by 1H-NMR Spectroscopy and Molecular-Dynamics Calculation
✍ Miyoko Kamigauchi; Kazuko Kawanishi; Makiko Sugiura; Hirofumi Ohishi; Toshimasa 📂 Article 📅 2008 🏛 John Wiley and Sons 🌐 German ⚖ 457 KB

## Abstract To prevent the precipitation reaction between glycyrrhizin (**1**) and berberine (**3**) in the decoctions of __Glycyrrhiza__/__Coptis__ rhizome or __Glycyrrhiza__/__Phellodendron__ bark, the presence of cyclodextrin (CD) in the mixture was proven to be effective. The preventing effect