the charge transfer (ct) complex formation of benzonitrile as acceptor with the aromatic donors o-, m-, p-xylene and ethylbenzene in ccl4 solutions is investigated by chemical shift measurements relative to an external reference. the equilibrium parameters, q and dad of their weak molecular complexes, as found numerically modified cresswel- allred (c-a) method, is compared with graphically scat...

Zunyite [Al13Si5O20(OH,F)18Cl] possesses an unusual combination of an Al13O16(OH)24 Keggin structure and a Si5O16 pentamer unit. We used 19F, 27Al, 29Si MAS and 27Al MQMAS NMR spectroscopy of a series of samples with varying Al:Si and F:OH ratios to investigate the degree of atomic order in zunyite. The quadrupole coupling constant (CQ) and asymmetry parameter ( ) obtained from simulations of 2...

The grafting reaction between a trifunctional silylating agent and two kinds of 2:1 type layered silicates was studied using FTIR, XRD, TGA, and 29Si CP/MAS NMR. XRD patterns clearly indicate the introduction of 3-aminopropyltriethoxysilane (gamma-APS) into the clay interlayer. In the natural montmorillonite, gamma-APS adopts a parallel-bilayer arrangement, while it adopts a parallel-monolayer ...

A combination of solid state 1H NMR chemical shift measurements and empirical chemical shift calculations has been used to interpret 1H solid state chemical shifts of a model peptide (Ala-Gly)15 for the crystalline domain of Bombyx mori silk fibroin in silk I and silk II structures, including a treatment of both intra- and intermolecular arrangements. Silk I and silk II are the structures of si...

Comparison of NMR chemical shift files can provide the researcher with valuable insights. For example, a comparison of NMR chemical shifts obtained for the same protein at various temperatures can provide insights into the protein's thermal stability (Roder, 1989). Also, shift comparisons of a large protein subjected to various detergents can show whether protein tertiary structure is disrupted...