✦ LIBER ✦

Measurement of the spin diffusion rate by depolarization of rare spins in CP MAS NMR

✍ Scribed by Xiaoling Wu; Xiulan Xie; Xuewen Wu

Publisher: Elsevier Science
Year: 1989
Tongue: English
Weight: 359 KB
Volume: 162
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(89)87053-8

No coin nor oath required. For personal study only.

✦ Synopsis

The proton spin diffusion rate in solid-state samples can be directly measured by using depolarization of rare spins in CP MAS NMR. In the slow decaying stage of the depolarization process, the magnetization of rigid protonated rare spins changes monoexponentially. This behavior can be reasonably described by using a one-dimensional random walk model. The mean flip-flop time of protons can be deduced from the exponential decay, and the spin diffusion coefficient can thus be estimated. In some typical rigid organic solids and crystallized polymers, the mean flip-flop time is found to be about 700 ps.

📜 SIMILAR VOLUMES

Ultrahigh spinning rates for a 7 mm roto

Ultrahigh spinning rates for a 7 mm rotor in multinuclear CP/MAS NMR spectroscopy of solids

✍ Vagn Langer; Preben Daugaard; Hans J Jakobsen 📂 Article 📅 1986 🏛 Elsevier Science ⚖ 191 KB

High-resolution dipolar NMR specra in ro

High-resolution dipolar NMR specra in rotating solids from depolarization of the rare spin magnetization

✍ P. Tekely; F. Montigny; D. Canet; J.J. Delpuech 📂 Article 📅 1990 🏛 Elsevier Science 🌐 English ⚖ 443 KB

A simple two-dimensional NMR procedure is used to obtain high-resolution chemical shift-dipolar correlated spectra of magicangle spinning solids. The dipolar spectrum in the second dimension is obtained without rotational sidebands as the result of Fourier transform of reverse cross-polarization evo

Slow-Down of 13C Spin Diffusion in Organ

Slow-Down of 13C Spin Diffusion in Organic Solids by Fast MAS: A CODEX NMR Study

✍ D. Reichert; T.J. Bonagamba; K. Schmidt-Rohr 📂 Article 📅 2001 🏛 Elsevier Science 🌐 English ⚖ 95 KB

One- and two-dimensional 13C exchange nuclear magnetic resonance experiments under magic-angle spinning (MAS) can provide detailed information on slow segmental reorientations and chemical exchange in organic solids, including polymers and proteins. However, observations of dynamics on the time scal

On the Application of the Spin-Locking T

On the Application of the Spin-Locking Technique for NMR Self-Diffusion Measurements by Pulsed Field Gradients

✍ Dipl.-Phys. A. Germanus; Prof. Dr. sc. H. Pfeifer; Dr. rer. nat. W. Heink; Doz. 📂 Article 📅 1983 🏛 John Wiley and Sons 🌐 English ⚖ 276 KB 👁 2 views

An improved NMR spin-echo apparatus for

An improved NMR spin-echo apparatus for the measurement of self-diffusion coefficients: The diffusion of water in aqueous electrolyte solutions

✍ K.R Harris; R Mills; P.J Back; D.S Webster 📂 Article 📅 1978 🏛 Elsevier Science ⚖ 679 KB

31P solid-state NMR study of spin diffus

31P solid-state NMR study of spin diffusion in the molecular sieve VPI-5 using variable-speed MAS

✍ Waclaw Kolodziejski; Heyong He; Jacek Klinowski 📂 Article 📅 1992 🏛 Elsevier Science 🌐 English ⚖ 614 KB

Hydrated aluminophosphate molecular sieve VPI-5 has been studied by "P solid-state NMR with variable-speed magic-angle spinning, Cross-polarization and two-dimensional spin-diffusion spectra were used to assign NMR signals to particular phosphorus sites in the structure in the P63 space group. The a