scholarly journals Assessing the One-Bond Cα–H Spin–Spin Coupling Constants in Proteins: Pros and Cons of Different Approaches

2020 ◽  
Vol 124 (5) ◽  
pp. 735-741
Author(s):  
Agustina Arroyuelo ◽  
Osvaldo A. Martin ◽  
Harold A. Scheraga ◽  
Jorge A. Vila
Keyword(s):  
Coupling Constants ◽  
Spin Coupling ◽  
Pros And Cons ◽  
Spin Coupling Constants ◽  
The One ◽  
Spin Spin Coupling

scholarly journals An efficient DFT method of predicting the one-, two- and three-bond indirect spin–spin coupling constants involving a fluorine nucleus in fluoroalkanes

RSC Advances ◽  
2016 ◽  
Vol 6 (86) ◽  
pp. 82783-82792 ◽  
Author(s):  
Adam Gryff-Keller ◽  
Przemysław Szczeciński
Keyword(s):  
Nuclear Spin ◽  
Dft Method ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Fluorine Nucleus ◽  
Spin Coupling Constants ◽  
Experimental Values ◽  
The One ◽  
Spin Spin Coupling

The values of the indirect nuclear spin–spin coupling constants for a series of aliphatic fluorocompounds have been calculated using DFT-based methods and compared with the experimental values of these parameters.

Relativistic effects in the one-bond spin-spin coupling constants involving selenium

2014 ◽  
Vol 52 (9) ◽  
pp. 500-510 ◽  
Author(s):  
Irina L. Rusakova ◽  
Yury Yu. Rusakov ◽  
Leonid B. Krivdin
Keyword(s):  
Relativistic Effects ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spin Coupling Constants ◽  
The One ◽  
Spin Spin Coupling

The conformational properties of some phenyl esters. Molecular orbital and nuclear magnetic resonance studies

1987 ◽  
Vol 65 (9) ◽  
pp. 2175-2178 ◽  
Author(s):  
Ted Schaefer ◽  
Glenn H. Penner
Keyword(s):  
Chemical Shifts ◽  
Phenyl Group ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Ambient Temperatures ◽  
Spin Coupling Constants ◽  
The One ◽  
Internal Barriers ◽  
Spin Spin Coupling ◽  
Planar Conformer

Extensive, geometry-optimized, STO-3G MO computations on phenyl formate imply a strongly nonplanar Z conformer (C=O bond cis to the phenyl group) at ambient temperatures. The internal barrier to rotation about the C(1)—O bond in this conformer is computed as V/kJ mol−1 = (−5.17 ± 0.27) sin2 θ − (2.42 ± 0.27) sin2 2θ, θ being zero for the planar conformer; the twofold is nearly twice as large as the fourfold component. The expectation value of θ is 58° at 300 K. The spin–spin coupling constants over six bonds between 13C and I9F nuclei in 4-fluorophenyl formate, acetate, propionate, and isobutyrate, as well as in the 2,6-dichloro-4-fluorophenyl acetate, are adduced as evidence for nonplanar conformers of these molecules. The magnitudes of these six-bond coupling constants are consistent with internal barriers to rotation about the C(1)—O bonds, which are similar in magnitude to those given by the computations on the Z conformer of phenyl formate. The energies of the planar and nonplanar E conformers, as well as the interconversion energies for [Formula: see text] isomerization, are computed. Small amounts of the nonplanar E conformer are predicted at ambient temperatures. The 13C chemical shifts and the one-bond 13C, 19F coupling constants are consistent, respectively, with only minor variations in the conformational behavior of the ester moieties caused by the fluorine substituent and by changes in the structures of these moieties themselves.

Vibrational and thermal averaging of the indirect nuclear spin-spin coupling constants of CH4, SiH4, GeH4 and SnH4

1997 ◽  
Vol 91 (5) ◽  
pp. 897-907 ◽  
Author(s):  
SHEELA KIRPEKAR ◽  
THOMAS ENEVOLDSEN ◽  
JENS ODDERSHEDE ◽  
WILLIAM RAYNES
Keyword(s):  
Nuclear Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling
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