Proximity and bond orientation effects on long-range proton-fluorine nuclear spin-spin coupling constants

1975 ◽  
Vol 97 (16) ◽  
pp. 4545-4552 ◽  
Author(s):  
R. E. Wasylishen ◽  
M. Barfield

1983 ◽  
Vol 61 (12) ◽  
pp. 2779-2784 ◽  
Author(s):  
Ted Schaefer ◽  
Kirk Marat ◽  
James Peeling ◽  
Richard P. Veregin

The magnitudes of nJ(C, F) for n = 3, 4, 5 bonds are remeasured for benzotrifluoride. The signs of 2J(C, F) and 3J(C, F) are determined for 4-chloro-3,5-dinitrobenzotrifluoride and that of 5J(C, F) for 2-amino-3,5-dibromobenzotrifluoride. 4J(C, F) is not observable in these compounds. The contact contributions to nJ(C, F) are calculated for benzotrifluoride by INDO MO FPT. The long-range coupling constants are discussed in terms of the mechanisms which transmit nuclear spin state information. It seems that 5J(C, F) is a σ–π coupling, 4J(C, F) is a composite of a and σ–π components of opposite sign, and that 3J(C, F) has a Karplus behaviour modified by a σ–π contribution.



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


2021 ◽  
Vol 6 (22) ◽  
pp. 5451-5465
Author(s):  
Antonio P. Santos Neto ◽  
Roberto Rivelino ◽  
Gabriel I. Pagola ◽  
Patricio F. Provasi


1981 ◽  
Vol 44 (1) ◽  
pp. 54-61 ◽  
Author(s):  
W Biffar ◽  
T Gasparis-ebeling ◽  
H Nöth ◽  
W Storch ◽  
B Wrackmeyer


1994 ◽  
Vol 98 (36) ◽  
pp. 8858-8861 ◽  
Author(s):  
C. Vizioli ◽  
M. C. Ruiz de Azua ◽  
C. G. Giribet ◽  
R. H. Contreras ◽  
L. Turi ◽  
...  


1969 ◽  
Vol 47 (9) ◽  
pp. 1507-1514 ◽  
Author(s):  
T. Schaefer ◽  
S. S. Danyluk ◽  
C. L. Bell

The signs of all proton–proton and proton–fluorine spin–spin coupling constants in 2-fluoro-3-methylpyridine have been determined by double and triple resonance experiments. The signs of the longrange coupling constants, JH,CH3 and JF,CH3 are the same as in fluorotoluene derivatives. Their magnitudes are consistent with the assumption that the nitrogen atom primarily polarizes the σ bonds in the molecule, leaving the π contribution to the long-range coupling relatively unaffected.





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