Chemical-shift tensors of heavy nuclei in network solids: a DFT/ZORA investigation of 207Pb chemical-shift tensors using the bond-valence method

Accurate computation of 207Pb magnetic shielding principal components is within the reach of quantum chemistry methods by employing relativistic ZORA/DFT and cluster models adapted from the bond valence model.

Download Full-text

A revisit of the bond valence model makes it universal

Physical Chemistry Chemical Physics ◽

10.1039/d0cp02434a ◽

2020 ◽

Vol 22 (25) ◽

pp. 13839-13849 ◽

Cited By ~ 2

Author(s):

Elena Levi ◽

Doron Aurbach ◽

Carlo Gatti

Keyword(s):

Quantum Chemistry ◽

Chemical Bond ◽

Bond Valence ◽

Bond Orders ◽

Chemistry Data ◽

Bond Valence Model

The application of Pauling's principles to any type of chemical bond can be validated using recent quantum chemistry data (bond orders), thus making them universal.

Download Full-text

Probing solid iminobis(diorganophosphine chalcogenide) systems with multinuclear magnetic resonance

Canadian Journal of Chemistry ◽

10.1139/v08-150 ◽

2009 ◽

Vol 87 (1) ◽

pp. 348-360 ◽

Cited By ~ 1

Author(s):

Bryan A Demko ◽

Roderick E Wasylishen

Keyword(s):

Solid State ◽

Chemical Shift ◽

Solid State Nmr ◽

Magnetic Shielding ◽

Chemical Shift Tensors ◽

X Ray ◽

X Ray Crystallography ◽

Shielding Tensor ◽

Nuclear Magnetic Shielding Tensors ◽

Nuclear Magnetic

A 31P and 77Se solid-state NMR investigation of the iminobis(diorganophosphine chalcogenide) HN(R2PE)2 (R = Ph,iPr; E = O, S, Se) systems is presented. The NMR results are discussed in terms of the known HN(R2PE)2 structures available from X-ray crystallography. The phosphorus chemical shift tensors are found to be sensitive to the nature of the alkyl and chalcogen substituents. The nature of the R group also influences the selenium chemical shift tensors of HN(R2PSe)2 (R = Ph, iPr), which are shown to be sensitive to hydrogen bonding in the dimer structure of HN(Ph2PSe)2 and to the presence of disorder in the case of HN(iPr2PSe)2. Scalar relativistic ZORA DFT nuclear magnetic shielding tensor calculations were performed yielding the orientations of the corresponding chemical shift tensors. A theoretical investigation into the effect of the E-P···P-E “torsion” angle on the phosphorus and selenium chemical shift tensors of a truncated HN(Me2PSe)2 system indicates that the electronic effect of the alkyl group on the respective nuclear magnetic shielding tensors are more important than the steric effect of the E-P···P-E torsion angle.Key words: iminobis(diorganophosphine chalcogenide), solid-state NMR, 31P NMR, 77Se NMR, ZORA DFT.

Download Full-text

Calculation of chemical-shift tensors of heavy nuclei: a DFT/ZORA investigation of 199Hg chemical-shift tensors in solids, and the effects of cluster size and electronic-state approximations

Physical Chemistry Chemical Physics ◽

10.1039/c4cp01682c ◽

2014 ◽

Vol 16 (27) ◽

pp. 14298-14308 ◽

Cited By ~ 18

Author(s):

Fahri Alkan ◽

C. Dybowski

Keyword(s):

Chemical Shift ◽

Electronic State ◽

Cluster Size ◽

Cluster Method ◽

Molecular Cluster ◽

Heavy Nuclei ◽

Chemical Shielding ◽

Solid Materials ◽

Chemical Shift Tensors

A ZORA/DFT investigation of the NMR chemical shielding of a suite of 199Hg-containing solid materials shows the importance of calculations with the molecular-cluster method.

Download Full-text

Phosphorus-31 NMR studies of several phosphines in the solid state

Canadian Journal of Chemistry ◽

10.1139/v89-297 ◽

1989 ◽

Vol 67 (11) ◽

pp. 1909-1913 ◽

Cited By ~ 20

Author(s):

Glenn H. Penner ◽

Roderick E. Wasylishen

Keyword(s):

Chemical Shift ◽

Principal Components ◽

Chemical Shift Tensor ◽

Cross Polarization ◽

X Ray Diffraction ◽

Nmr Studies ◽

Chemical Shift Tensors ◽

X Ray ◽

Cp Mas Nmr ◽

Proton Decoupling

Phosphorus-31 NMR powder spectra and high resolution MAS spectra have been obtained for a number of solid phosphines under conditions of high-power proton decoupling and cross-polarization. The principal components of the 31P chemical shift tensor obtained from static powder spectra or slow MAS spectra are discussed in terms of the known structures of many of the phosphines. The CP/MAS 31PNMR spectra are used to determine the number of crystallographically nonequivalent molecules in the unit cell. The NMR results are consistent with data available from X-ray diffraction. In one case there is evidence of polymorphism. Keywords: 31P NMR of solid phosphines, principal components of 31P chemical shift tensors, crystallographic nonequivalence from 31P CP/MAS NMR.

Download Full-text

A phosphorus-31 NMR study of solid carbonylhydridotris(triphenylphosphine)rhodium(I). Unusual MAS sideband intensities in second-order NMR spin systems

Canadian Journal of Chemistry ◽

10.1139/v92-114 ◽

1992 ◽

Vol 70 (3) ◽

pp. 863-869 ◽

Cited By ~ 7

Author(s):

Gang Wu ◽

Roderick E. Wasylishen ◽

Ronald D. Curtis

Keyword(s):

Chemical Shift ◽

Spin System ◽

Principal Components ◽

Nmr Spectra ◽

Magic Angle Spinning ◽

Chemical Shift Tensor ◽

Magic Angle ◽

Nmr Spectrum ◽

Chemical Shift Tensors ◽

Nmr Study

The CP/MAS 31P NMR spectrum of carbonylhydridotris(triphenylphosphine)rhodium(I), RhH(CO)(PPh3)3 (1), can be described as a tightly coupled ABMX spin system (X = 103Rh). In contrast to the solution 31P NMR spectrum, the three equatorial phosphorus nuclei are nonequivalent in the solid state and this structural feature allows us to measure the two-bond spin–spin couplings, 2J(31P,31P). A new method is proposed for extracting the principal components of the chemical shift tensor from slow MAS NMR spectra in a tightly J-coupled two-spin system. For compound 1, the principal components of the 31P chemical shift tensors calculated using this method are in good agreement with those obtained from NMR spectra of a static sample. The principal components of the 31P chemical shift tensors determined for 1 are compared with those reported previously for Wilkinson's catalyst, RhCl(PPh3)3. The δ22 component of the 31P chemical shift tensors in 1 shows the largest variation with structure. This is ascribed to differences in the orientation of the P—Cipso bond about the equatorial plane of the trigonal bipyramidal structure. Keywords: rhodium–phosphine compounds, AB spin system, 31P chemical shift tensor, magic-angle spinning, molecular structure.

Download Full-text