Magic-angle spinning NMR

MAS NMR magic angle spinning nuclear magnetic resonance... 

A1 mas NMR (magic angle spinning nuclear magnetic resonance) measurements of the samples were carried out on a Bruker AC400 spectrometer. 

The amplitudes of ring- and main-chain motions of a variety of polystyrenes have been established from the 13C NMR magic-angle spinning sideband patterns of dipolar and chemical shift tensors. The frequencies of the same motions have been determined by TiCC) and TjpCC) experiments. The most prevalent motion in these polymers is restricted phenyl rotation with an average total displacement of about 40°. Both the amplitude and frequency of this motion vary from one substituted polystyrene to another, and from site to site within the same polystyrene. A simple theory correlates the observed ring dipolar patterns with s. 

The chemical shift anisotropies for the carbonyl and aromatic carbons of Hytrel were reconstructed from a Herzfeld-Beiger analysis (24) of the intensities of the sidebands from NMR magic angle spinning experiments. The results in Table III indicate that the carbonyl carbon chemical shift anisotropy is axially symmetric for each terephthalate ester. We attribute this axial symmetry to a general property of terephthalate esters, rather than as a consequence of molecular motion, as the highly crystalline dimethyl terephthalate also has an axially symmetric carbonyl carbon chemical shift tensor. 

The Si NMR [19] cross-polarization magic-angle spinning (CP MAS) and H NMR magic-angle spinning with multiple-pulsed line narrowing (CRAMPS for combined rotation and multiple-pulse spectroscopy) techniques of Maciel et al. [20,21] indicate that FS-662... 

Figure 8 500 MHz H NMR magic angle spinning spectra of prostatic tissue from humans with malignant prostate cancer sampled by transurethral radical prostatectomy (TURP) (A), or needle biopsies (B, C) contrasted with that of a benign prostatic hyperplasia (BPH) patient sampled via radical prostatectomy (D). Spectrum (C) is different, as the needle has sampled a different region of the prostate. The spectrum of the prostate tissue from the BPH patient (D) displays higher levels of citrate but lower lipid levels relative to spectra (A) and (C) from the malignant cancer patients. (See Tomlins AM, Foxall PJD, Lindon JC, Lynch MJ, Spraul M, Everett JR, and Nicholson JK (1998). Analytical Communications 35 113-115).

Martian crustal materials Ubiquitous, fine grained dust found on the surface of Mars believed to consist of silicates, iron oxide, carbonates and clays MAS-NMR Magic angle spinning-nuclear magnetic resonance... 

Key Words Proton exchange membrane fuel cells. Direct methanol fuel cells. Protonconducting materials, NMR, Magic angle spinning NMR, Pulsed field gradient NMR, Rel-... 

A1 MAS NMR Magic angle spinning nuclear magnetic resonance of the aluminum nucleus (spectroscopy)... 

Mastikhin VM, Mudrakovskii IL, Nosov AV. H-NMR magic angle spinning (MAS) studies of heterogeneous catalysis. Prog Nucl Magn Reson Spectrosc 1991 23 259-99. 

Kennedy GJ, Afeworki M, Calabro DC, Chase CE, Smiley RJJ. H MAS NMR (magic-angle spinning nnclear magnetic resonance) techniques for the quantitative determination of hydrogen types in solid catalysts and supports. Appl Spectrosc 2004 58 698-704. 

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