A theoretical study of multinuclear coupling constants in pyrazoles

2005 ◽  
Vol 43 (12) ◽  
pp. 985-991 ◽  
Author(s):  
Rosa M. Claramunt ◽  
Dionisia Sanz ◽  
Ibon Alkorta ◽  
José Elguero
Keyword(s):  
Theoretical Study ◽  
Coupling Constants

Experimental and Theoretical-Study of Carbon-Fluorine Couplings in the NMR-Spectra of 2-Fluoroaryl Ketones

1985 ◽  
Vol 38 (12) ◽  
pp. 1779 ◽  
Author(s):  
RH Contreras ◽  
CG Giribet ◽  
MA Natiello ◽  
J Perez ◽  
ID Rae ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Side Chain ◽  
Aliphatic Carbon ◽  
Spin Coupling Constants ◽  
Fermi Contact ◽  
Spin Spin Coupling ◽  
Fermi Contact Term ◽  
Good Agreement

Calculations by the IPPP-INDO method give the spin-spin coupling constants for the side-chain carbons, 3JCF and 4JCF, as 4.97 and 6.86 Hz respectively with substantial contributions to through-space coupling from the pathway CO-C-H…F. The observed values for 1-(2- fluorophenyl ) ethanone , 3.3 and 7.2 Hz, and for 1-(2,5- difluorophenyl ) ethanone , 3.7 and 7.3 Hz, are in good agreement with these predictions. Two compounds, a dihydroindenone and a naphthalenone, in which this pathway cannot be effective, show no fluorine coupling to the aliphatic carbon next to the carbonyl and the values of 3JCF are reduced to 2.2 and 2.5 Hz, consistent with the loss of a through-space Fermi contact term of the kind described above.

scholarly journals One-bond 1 J (15 N,H) coupling constants at sp2 -hybridized nitrogen of Schiff bases, enaminones and similar compounds: A theoretical study

2020 ◽  
Vol 58 (8) ◽  
pp. 750-762
Author(s):  
Poul Erik Hansen ◽  
Bahjat A. Saeed ◽  
Rita S. Rutu ◽  
Teobald Kupka
Keyword(s):  
Schiff Bases ◽  
Theoretical Study ◽  
Coupling Constants

Experimental and theoretical study of substituent effects on3J(13C1-1H) coupling constants in 1-X-bicyclo[1.1.1]pentanes

1996 ◽  
Vol 9 (3) ◽  
pp. 168-178 ◽  
Author(s):  
Ernest W. Della ◽  
Ian J. Lochert ◽  
N�lida M. Peruchena ◽  
Gustavo A. Aucar ◽  
Rub�n H. Contreras
Keyword(s):  
Theoretical Study ◽  
Substituent Effects ◽  
Coupling Constants
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