Determination of NMR spin coupling constants using J-cross polarization. A comment on "J-Cross polarization in silanes

1979 ◽  
Vol 101 (15) ◽  
pp. 4058-4059 ◽  
Author(s):  
G. C. Chingas ◽  
R. D. Bertrand ◽  
A. N. Garroway ◽  
W. B. Moniz
Keyword(s):  
Coupling Constants ◽  
Spin Coupling ◽  
Cross Polarization ◽  
Spin Coupling Constants

Stereochemical Determination of Acyclic Structures Based on Carbon−Proton Spin-Coupling Constants. A Method of Configuration Analysis for Natural Products

1999 ◽  
Vol 64 (3) ◽  
pp. 866-876 ◽  
Author(s):  
Nobuaki Matsumori ◽  
Daisuke Kaneno ◽  
Michio Murata ◽  
Hideshi Nakamura ◽  
Kazuo Tachibana
Keyword(s):  
Natural Products ◽  
Proton Spin ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spin Coupling Constants

A proton magnetic resonance determination of the small rotational barriers about the C—Si bond in phenyl derivatives of chloro and methyl silanes

1977 ◽  
Vol 55 (3) ◽  
pp. 557-561 ◽  
Author(s):  
William J. E. Parr ◽  
Ted Schaefer
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Molecular Orbital Calculations ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling ◽  
Derivatives Of ◽  
Low Energy Conformations

The long-range spin–spin coupling constants between protons bonded to silicon and ring protons in C6H5SiH3, C6H5SiH2Cl, C6H5SiH2CH3, C6H5SiHCl2, and C6H5SiH(CH3)2 are determined from the proton magnetic resonance spectra of benzene solutions. A hindered rotor treatment of the barrier to internal rotation about the C—Si bond, in conjunction with the coupling constants over six bonds, allows the deduction of the low-energy conformations for C6H5SiH(CH3)2 and for C6H5SiHCl2, as well as of barriers of 1.0 ± 0.2 kcal/mol. The approach becomes less reliable for C6H5SiH2CH3 and for C6H5SiH2Cl and, particularly for the latter compound, the derived barrier is very likely an upper limit only. Ab initio molecular orbital calculations of the conformational energies are reported for C6H5SiH3, C6H5SiH2Cl, and for C6H5SiHCl2.

scholarly journals Long-range proton–carbon coupling constants for the determination of the stereochemical structure of organic compounds.

2021 ◽  
pp. 125-131
Author(s):  
Anwar, E. M. Noreljaleel
Keyword(s):  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Long Range ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Spectroscopy Method ◽  
Stereochemical Structure ◽  
New Methods ◽  
Spin Coupling Constants

A new methods for elucidating stereochemistry of organic compounds was developed on the basis of long-range proton–carbon coupling constants (2,3JC,H) and interpreting spin-coupling constants (3JH,H). Reaction of compound containing pyrin ring with nucleophile reagent was done to open the ring. HSQC-TOCSY experiments one of the new NMR spectroscopy method used to measure this values of spin-coupling constants and elucidating the stereochemistry of the product.

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