Proton solid-state NMR

No.l, 12th Jan. 1999, p.167-80 CRYSTALLINITY AND MICROSTRUCTURE OF PLASTICISED PVC. A CARBON 13 AND PROTON SOLID STATE NMR STUDY... 

V. Chevelkov, K. Rehbein, A. Diehl, B. Reif, Ultrahigh resolution in proton solid-state NMR spectroscopy at high levels of deuteration, Angew. Chem. Int. Ed. 45 (2006) 3878-3881. 

NMR instrumentation consists of three chief components a magnet, a spectrometer console, and a probe. While in the past much solid state NMR research was conducted on home-built equipment, the current trend is toward the acquisition of commercial systems. The magnets used for solid state NMR applications generally are superconducting solenoids with a cylindrical bore of 89-mm diameter. The most common field strengths available, 4.7, 7.0, 9.4, and 11.7 Tesla, correspond to proton resonance frequencies near 200, 300, 400, and 500 MHz, respectively. 

High-Resolution Solid-State NMR Study of Reversible 1,5-Proton Shifts in Organic Solids [90MRC(S)29] NMR of Pyrazoles ... 

Different solid-state NMR techniques CPMAS NMR, the second moment of the signal, the spin-lattice relaxation time in the rotating frame T p) were combined to reach the conclusion that in the case of por-phine H2P the double-proton transfer is followed by a 90° rotation within the crystal (see Scheme 2). 

Using proton NMR of solutions, the composition of polymers can be analyzed.47 Carbon-13 NMR spectroscopy is a useful tool for studying the sequence length of segments in copolymers and thereby determining the blockiness of the copolymer. With solid-state NMR, the mobility of chain segments can be studied and the crystallinity determined. 

Vinogradov E, Madhu PK, Vega S (2005) Strategies for High-Resolution Proton Spectroscopy in Solid-State NMR. 246 33-90... 

Table. 1 defects and proton titration using Solid State NMR. 

No solid state NMR experiment is able to obtain spectra comparable to those routinely recorded in the liquid state. Thus multiplets become broad singlets and, if close together, overlap to give a broad signal envelope . While the differentiation of aromatic and aliphatic protons is simple, the information available is, from the point of view of structure determination, very limited. Thus we shall not provide an example. 

Shi et al.71 have assigned the backbone and side-chain chemical shifts for 103 of 238 residues of proteorhodopsin using solid state NMR spectroscopy. Analysis of the chemical shifts has allowed determination of protonation states of several carboxylic acids as well as boundaries and distortions of trans-membrane a-helices and secondary structure elements in the loops. It has been shown that internal Asp227, making a part of the counterion, is ionised, while Glul42 located close to the extracellular surface is neutral. 

Magnetization transfer via proton-driven-spin-diffusion (PDSD) in MAS NMR is not by any means a new experiment. It was introduced in the early 1980s by Maciel and coworkers [136] and later used, described, and analyzed by numerous groups in relation to, e.g., biological solid-state NMR. In its original form, the experiment consists of a couple of oppositely phase n/2 pulses bringing the low-y... 

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