Berechnung der Spin-Spin-Koppelkonstante von HD mit nichtsingulärem Kontaktoperator / Calculation of the NMR Coupling Constant in HD by Using a Nonsingitlar Contact Operator

1973 ◽  
Vol 28 (11) ◽  
pp. 1866-1868 ◽  
Author(s):  
W. Sänger ◽  
J. Voitländer
Keyword(s):  
Delta Function ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Coupling Energy ◽  
First Order ◽  
Order Energy ◽  
Spatial Part ◽  
Fermi Contact ◽  
Contact Operator ◽  
Spin Spin Coupling

The Fermi contact contribution to the nuclear spin-spin coupling constant of HD is calculated variationally. Instead of the delta-function a modified nonsingular contact spatial part is used. The self-coupling energy becomes finite and the variation of the whole second-order energy due to a non- singular first-order perturbed trial function can be carried out.

On the Convergence of the Calculated Spin-spin Coupling Constant of HD

1979 ◽  
Vol 34 (10) ◽  
pp. 1158-1159
Author(s):  
H. P. Trivedi
Keyword(s):  
Cross Coupling ◽  
Second Order ◽  
The Self ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Coupling Energy ◽  
Order Energy ◽  
The Cross ◽  
Spin Spin Coupling

Abstract It is shown that the concurrence of the results obtained by varying the self coupling energy, the total second order energy and the cross coupling energy independently can be readily accomplished. In addition, it is possible to arrange to obtain any pre-specified value for the coupling constant. On this basis it is suggested that it might be dangerous to construe the concurrence of calculated results as an indication of convergence in practice.

Anisotropy of indirect spin–spin coupling constants from nuclear magnetic resonance powder patterns of rigid solids. 1J(31P,199Hg) in [HgP(o-tolyl)3(NO3)2]2

1988 ◽  
Vol 66 (8) ◽  
pp. 1821-1823 ◽  
Author(s):  
Glenn H. Penner ◽  
William P. Power ◽  
Roderick E. Wasylishen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constants ◽  
Fermi Contact ◽  
Spin Spin Coupling ◽  
Contact Mechanism ◽  
Nuclear Magnetic

The anisotropy of the indirect 31P,199Hg spin–spin coupling constant, ΔJ, in solid [HgP(o-tolyl)3(NO3)2]2 is obtained from an analysis of the 31P nuclear magnetic resonance powder pattern. The value of ΔJ, 5170 ± 250 Hz, is large and indicates that mechanisms other than the Fermi contact mechanism are important for this spin–spin coupling. The powder spectrum also indicates that the absolute sign of 1J(31P,199Hg) is positive.

INDO MO Calculations of the Conformational Dependence of the vicinal 13C,H Spin–Spin Coupling Constant in Propane

1972 ◽  
Vol 50 (16) ◽  
pp. 2710-2712 ◽  
Author(s):  
R. Wasylishen ◽  
T. Schaefer
Keyword(s):  
Coupling Constants ◽  
Spin Coupling ◽  
Molecular Orbital Theory ◽  
Coupling Constant ◽  
Mo Calculations ◽  
Orbital Theory ◽  
Angle Dependence ◽  
Proton Coupling ◽  
Fermi Contact ◽  
Spin Spin Coupling

Molecular orbital theory at the INDO level of approximation is used to calculate the Fermi contact contribution to three-bond carbon–proton coupling constants in propane. The calculations predict a dihedral angle dependence of 3J(13C,H) in the 13C—C—C—H fragment similar to that observed for 3J(H,H), 3J(19F,H), and for 3J(31P,H) in the saturated X—C—C—H fragments.

NMR Spin-Spin Coupling in HD

1975 ◽  
Vol 30 (11) ◽  
pp. 1491-1492 ◽  
Author(s):  
W. Sänger ◽  
J. Voitländer
Keyword(s):  
Nuclear Spin ◽  
Short Range ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Spatial Part ◽  
Short Range Part ◽  
Range Part ◽  
Spin Spin Coupling ◽  
O 10

The contact contribution to the nuclear spin-spin coupling constant in HD is evaluated variationally by using the nonsingular contact spatial part fm(r,a) =exp(-r/a)/2 a3, a=O (10-6) a.u. JHD is calculated to be 39 Hz and is independent of the sharp short-range part of the trial firstorder wavefunction to the order O (a)

Indirekte Kernspinkopplung zwischen Protonen und Elementen der IV. Gruppe

1964 ◽  
Vol 19 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Herbert Dreeskamp
Keyword(s):  
Electron Density ◽  
Strong Correlation ◽  
Valence Electron ◽  
Spin Coupling ◽  
Atomic Data ◽  
Coupling Constant ◽  
Methyl Group ◽  
Hartree Fock ◽  
Fermi Contact ◽  
Spin Spin Coupling

The indirect spin-spin coupling between protons and Ge73, spin 9/2, in the tetraedric molecule GeH4 has been measured. JGe-H = 97,6 Hz. Introducing the normalized coupling constant J′ which is obtained by dividing the measured coupling constant by the product of the magnetogyric ratios of the coupling nuclei, a strong correlation is found between this quantity for XH4 (X = C, Si, Ge, Sn, Pb) and the electron density of the valence electron at the nucleus obtained from HARTREE-FOCK calculations or experimental atomic data. This demonstrates that at least in these cases the FERMI contact contribution is dominant. For the analogeous tetramethyl compounds the same relation holds only to the extend that the C - H coupling in the methyl group is constant.

Carbon-Nitrogen Spin-Spin Coupling in Diazomethane

1976 ◽  
Vol 31 (11) ◽  
pp. 1515-1518 ◽  
Author(s):  
W. Runge ◽  
J. Firl
Keyword(s):  
Coupling Constants ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Fermi Contact ◽  
Nitrogen Coupling ◽  
The One ◽  
Spin Spin Coupling ◽  
Contact Mechanism

The one-bond carbon-nitrogen coupling constant of diazomethane is reported. Analogies with carbon-carbon coupling constants in allenes are emphasized. CNDO/S-calculations are used as a support of the suggestions the C-N coupling in diazomethane to be dominated by the Fermi contact mechanism and the sign of the carbon-nitrogen-15 coupling constant to be negative

Equivalence of the Variational Criteria in the Calculation of the Nuclear Spin-Spin Coupling Constant of HD

1980 ◽  
Vol 35 (10) ◽  
pp. 1108-1109
Author(s):  
H. P. Trivedi
Keyword(s):  
Nuclear Spin ◽  
Cross Coupling ◽  
Second Order ◽  
The Self ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Order Energy ◽  
The Cross ◽  
Spin Spin Coupling

Abstract Using symmetry arguments it is shown that the variation of the self coupling, the cross coupling and the total second order energy are equivalent criteria for the calculation of the nuclear spin-spin coupling constant of HD and larger symmetric molecules. A previously given condition guaranteeing this equivalence is shown to be unnecessarily restrictive.

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