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...

Recent ab initio calculations of cobalt NMR shielding show that DFT-GIAO calculations using hybrid functionals are found to reproduce experimental values well. This method is used to calculate the variation of the cobalt NMR shielding tensor of sqaure pyramidal nitrosyl complexes with respect to the CoNO geometry and to differing basal ligands. The isotropic shielding is shown to have a large n...

A modified Freeman-Murray-Richards (FMR) correlation for the analysis of 59C0 NMR shielding parameters, 6(59C0) us. ( A V ~ , ~ ) ' / ' / A E ~ ~ , is formulated by combining the Ramsey shielding theory and the Townes and Dailey theory for the calculation of the nuclear quadrupole coupling constant. It is demonstrated that the experimental 59C0 NMR half-height linewidth is a useful parameter to...

A series of 11 oxovanadium(V) complexes mimicking the active site of vanadium haloperoxidases have been investigated by (51)V magic angle spinning NMR spectroscopy and density functional theory (DFT). The MAS spectra are dominated by the anisotropic quadrupolar and chemical shielding interactions; for these compounds, C(Q) ranges from 3 to 8 MHz, and delta(sigma) is in the range 340-730 ppm. Th...

The unrivaled combination of speed, accuracy, and ease of use make CAE software that employs the BEM ideally suited for analyses involving shielding of MRI and NMR systems.

This paper presents a new method to calculate solid-state effects on NMR chemical shifts. Using full crystal potentials, this new method (CPPCh) eliminates the need to arbitrarily select the point charges that are included in the calculations of the NMR chemical shieldings to take into account intermolecular effects. By eliminating the arbitrary selection of the point charges, the method provid...

A density functional method has been used to successfully predict the isotropic 59Co nuclear magnetic resonance (NMR) chemical shifts of the following anionic, cationic and neutral Co(III) complexes: [Co(CN)6], [Co(NH3)6], [Co(NO2)6], [Co(NH3)4CO3], Co(acac)3, and [Co(en)3]. Isotropic chemical shifts are wellreproduced by using Wachters’ cobalt basis set and uniform 6-31G* basis sets on the lig...

Density functional theory (DFT) calculations of the magnetic shielding in solid state nuclear magnetic resonance (NMR) experiments provide an important contribution for the understanding of the experimentally observed chemical shifts. In this work we focus on the relation between atomic and orbital character of the valence and conduction band wave functions and the S NMR shielding in sulfides a...

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 ...

Chemical shift requires the knowledge of both the sample and a reference magnetic shielding. In few cases as nitrogen (15N), the standard experimental reference corresponds to its liquid phase. Theoretical estimate of NMR magnetic shielding parameters of compounds in their liquid phase is then mandatory but usually replaced by an easily-get gas phase value, forbidding direct comparisons with ex...