✦ LIBER ✦

Residual chemical-shift effects in spin-echo NMR powder patterns of homonuclear dipolar-coupled spins

✍ Scribed by Toshihito Nakai; Charles A. McDowell

Publisher: Elsevier Science
Year: 1994
Tongue: English
Weight: 406 KB
Volume: 217
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(93)e1359-o

No coin nor oath required. For personal study only.

✦ Synopsis

The effect of the spin-echo pulse sequence on homonuclear dipolar-coupled spins in solids has been studied. Precise analysis has revealed that the sequence may not yield simple Pake doublets but rather complicated patterns because of the imperfect refocusing of the chemical shifts. This strong-coupling effect has been verified experimentally through the measurement of the "P two-dimensional spin-echo powder pattern for polycrystalline tetraphenyldiphosphine; our choice of tetraphenyldiphosphine was fortunate because it transpired that the non-parallel chemical-shift tensors of the two 31P nuclei in the compound yield the desired residual chemical-shift effects.

📜 SIMILAR VOLUMES

A Robust Technique for Two-Dimensional S

A Robust Technique for Two-Dimensional Separation of Undistorted Chemical-Shift Anisotropy Powder Patterns in Magic-Angle-Spinning NMR

✍ S-F. Liu; J-D. Mao; K. Schmidt-Rohr 📂 Article 📅 2002 🏛 Elsevier Science 🌐 English ⚖ 257 KB

A robust magic-angle-spinning experiment for separating undistorted, quasi-static chemical-shift powder patterns is presented. It is derived from the technique of R. Tycko, G. Dabbagh, and P. Mirau (1989, J. Magn. Reson. 85, 265), but uses 360 • instead of 180 • pulses. In combination with a suitabl

Switching-angle sample-spinning NMR spec

Switching-angle sample-spinning NMR spectroscopy for obtaining powder-pattern-resolved 2D spectra: Measurements of 13C chemical-shift anisotropies in powdered 3,4-dimethoxybenzaldehyde

✍ T. Terao; T. Fujii; T. Onodera; A. Saika 📂 Article 📅 1984 🏛 Elsevier Science 🌐 English ⚖ 443 KB

The effect of the NMR spin-echo sequence

The effect of the NMR spin-echo sequence Py(90°)-τ-Py(180°) in solids containing different dipolar-coupled spin species: applications to KHF2 AND CsHF2

✍ M. Mortimer; E.A. Moore; D.C. Apperley; G. Oates 📂 Article 📅 1987 🏛 Elsevier Science 🌐 English ⚖ 524 KB

An experimental investigation of the effect of the NMR sequence P,( 90" )-r-P,( 180" ) in solids containing different types of dipolar-coupled spin species is reported. The experimental results suggest that the decay of the maximum spin-echo amplitude as a function of pulse spacing depends only on t

Thallium-205 spin lattice relaxation in

Thallium-205 spin lattice relaxation in dialkylthallium(III) derivatives: Importance of chemical shift anisotropy relaxation and effects on NMR spectra of coupled nuclei

✍ Frank Brady; Ray W. Matthews; Mark J. Forster; Duncan G. Gillies 📂 Article 📅 1981 🏛 Elsevier Science ⚖ 167 KB