A series of four anhydrous group 13 chloride salts has been studied by (35/37)Cl solid-state NMR spectroscopy and complementary quantum chemical calculations. Due to the large (35/37)Cl quadrupolar interactions in these salts, a high magnetic field (21.1 T) and the variable-offset QCPMG technique was used to obtain full chlorine central transition (m = -1/2 <--> 1/2) NMR spectra. Analyses of th...

Density functional theory (DFT) calculations of the magnetic shielding for solid state nuclear magnetic resonance (NMR) provide an important contribution for the understanding of experimentally observed signals. In this work, we present calculations of the Y NMR shielding in intermetallic compounds (YMg, YT, YTX, YT2X, YT2X2, Y2TB6, and Y2TSi3 where T represents various transition metals and X ...

NMR signals of 7Li, 23Na, 35C1, 39K , 79Br, 87Rb and 127I have been measured in various alkali and halogen salt powders relative to well defined aqueous solutions. W ith the known shielding constants of some of these solutions the nuclear magnetic shielding constants of the alkali and chlorine nuclei in crystalline powders were evaluated in the atomic reference scale. The theoretical values of ...

This paper demonstrates that the addition of chemical agents and carbon fibers to cement can greatly enhance the shielding effectiveness of the concrete. In addition to improving the shielding effectiveness, carbon fibers and chemical agents enhance the tensile and flexural strengths significant ly. As both carbon fibers and steel fibers are electrically conductive, both can be added to cement ...

Reactions of imidazolidine-2-thione (Imt), 1,3-diazinane-2-thione (Diaz) and 1,3-diazipane-2thione (Diap) with mercury(II) selenocyanate in acetonitrile resulted in formation of 2 : 1 complexes. Both solid state and solution NMR, confirm the exocyclic sulfur atom to be the donor in all cases. Hg shielding tensors and anisotropies were calculated from the solid-state NMR spectra. Based on the so...

We have evaluated the NMR shielding tensors for active site of oxidized ayurin Azurin is classified to atype I copper protein with ET functionality. We have computed NMR shielding tensor at .133LYP and IDlevels by usum 6-3IG basis set in the gas phase and in different solvents such as water, HMSO,Nitromethane, methanol, ethanol, acetone ,dicholoroethane. These solvents represent a wide range of...

the interaction of magnesium hydrate at the phosphate oxygen atom of the pyrimidine nucleotides (cmp,ump,dtmp) were studied at the hartree-fock level theory. we used lanl2dz basis set for mg and 6-31g* basis set for atoms.the basis set superposition error (bsse) begins to converge for used method/basis set. the gauge-invariant atomic orbital (giao) method and the continuous-set-of-gauge-transfo...

Mesoporous carbon materials were synthesized employing polymers and silica gels as structure directing templates. The basic physico-chemical properties of the synthetic mesoporous materials were characterized by (1)H and (13)C MAS solid-state NMR, X-ray diffraction, transmission electron microscopy (TEM) and nitrogen adsorption measurements. The confinement effects on small guest molecules such...

The isotropic (129)Xe nuclear magnetic resonance (NMR) chemical shift (CS) in Xe@C60 dissolved in liquid benzene was calculated by piecewise approximation to faithfully simulate the experimental conditions and to evaluate the role of different physical factors influencing the (129)Xe NMR CS. The (129)Xe shielding constant was obtained by averaging the (129)Xe nuclear magnetic shieldings calcula...

Cyclocondensation between 4,4`-bis(4-chlorobenzenesulfonyl)biphenyl and catechol, with subsequent chromatographic separation of the reaction products, led to isolation four novel ether-sulfone macrocycles (cyclic dimer, -trimer, -tetramer -pentamer). Similarly, cyclocondensation catechol a seven-ring diketone/disulfone monomer allowed two new aromatic ether-ketone-sulfone macrocycles, cyclic di...