2D Deuteron Exchange NMR and Stimulated Echoes: Molecular Dynamics of the Vacancy Diffusion in Polycrystalline Benzene
✍ Scribed by Olaf Isfort; Burkhard Geil; Franz Fujara
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 330 KB
- Volume
- 130
- Category
- Article
- ISSN
- 1090-7807
No coin nor oath required. For personal study only.
✦ Synopsis
Since in crystalline benzene the unit cell consists of four differfor the sequence (p/2É Y -t 1 -p/2É Y -t m -p/2É Y -D-p/ ently oriented molecules, the vacancy diffusion is expected to go 2É X -D-t 2 ). In the so-called preparation period, before the along with a corresponding molecular reorientation. Therefore, application of the pulse sequence, the sample builds up an 2 H NMR is able to yield detailed information about the time equilibrium magnetization. The first two pulses are separated scale and local geometry of this jump diffusion process. We have by the evolution period t 1 , during which the spins possess carried out 2 H NMR stimulated echo and 2D experiments. These the frequency v 1 relative to the Larmor frequency. During data, their fit to calculated spectra, and a comparison between the mixing period t m (t m ӷ t 1 ) the spins change their frethe ( 1D) stimulated echo treatment and the 2D analysis are quency from v 1 to v 2 due to the molecular dynamics under presented. ᭧ 1998 Academic Press investigation. The NMR signal is recorded within the detection period t 2 . The fourth pulse is applied as a refocusing pulse in order to circumvent receiver dead time. We used