Multiple - Quantum Magic - Angle Spinning NMR: A New Technique for Probing Quadrupolar Nuclei in Solids

Multiple-quantum magic-angle spinning and dynamic-angle spinning NMR spectroscopy of quadrupolar nuclei.

Several aspects of the Multiple-Quantum Magic-Angle Spinning (MQMAS) technique (L. Frydman and J.S. Harwood, J. Am. Chem. Soc., 117 (1995) 5367) are compared with Dynamic-Angle Spinning (DAS). Examples of MQMAS spectra are shown for I = 3/2 nuclei with CQ up to 3.6 MHz, and for 27Al (I = 5/2) with CQ up to 10 MHz. The MQMAS linewidth is largely independent of the magnitude of the homonuclear di...

Fundamentals of Multiple-Quantum Magic-Angle Spinning NMR on Half-Integer Quadrupolar Nuclei

Decoupling-induced recoupling in multiple-quantum magic-angle-spinning NMR spectra of quadrupolar nuclei

We report the observation of a new decoupling-induced recoupling phenomenon in multiple-quantum magic-angle-spinŽ . ning MQMAS NMR spectra of half-integer quadrupolar nuclei. The origin of the effect is identical to the second-order Ž . recoupling between dipolar and anisotropic chemical shielding interactions under continuous-wave CW spin decoupling, w Ž . x which is first observed by Ernst et...

Multiple-Quantum Magic- Angle Spinning NMR: A New Method for the Study of Quadrupolar Nuclei in Solids

Whereas solid state isotropic spectra can be obtained from spin-'/2 nuclei by fast magic-angle spinning (MAS), this methodology fails when applied on half-integer quadrupoles due to the presence of non-negligible secondorder anisotropic effects. Very recently, however, we have shown that the combined use of MAS and bidimensional multiple-quantum (MQ) spectroscopy can refocus these anisotropies;...

Residual dipolar couplings between quadrupolar nuclei in high resolution solid state NMR: Description and observations in the high-field limit

Nonsecular dipolar couplings between spin2 nuclei that are in close proximity to quadrupolar spins have been extensively documented in solid state nuclear magnetic resonance ~NMR!, particularly when involving directly bonded S5C, I5N spin pairs. These couplings arise due to the quadrupole-induced tilting of I’s nuclear spin quantization axes, and their most notable characteristic is that they c...

Solid state separated-local-field NMR spectroscopy on half-integer quadrupolar nuclei: principles and applications to borane analysis.

New multidimensional NMR methods correlating the quadrupolar and heteronuclear dipolar interactions affecting a half-integer quadrupolar spin in the solid state are introduced and exemplified. The methods extend separated-local-field magic-angle spinning (SLF MAS) NMR techniques that have been used successfully in spin-(1)/(2) spectroscopy to the study of S >/= (3)/(2) nuclei. In our implementa...