The Investigation of Cation–Anion Interactions by 39K Nuclear Magnetic Resonance

1972 ◽  
Vol 50 (23) ◽  
pp. 3926-3930 ◽  
Author(s):  
E. G. Bloor ◽  
R. G. Kidd

The 39K chemical shifts in a number of aqueous electrolyte solutions have been determined. These arise from the overlapping of the outer electron orbitals of the anion and cation during random ionic collisions. The magnitudes of the chemical shifts are shown to be directly proportional to the effectiveness of this overlap interaction.

1977 ◽  
Vol 42 (14) ◽  
pp. 2411-2418 ◽  
Author(s):  
William Kitching ◽  
Maxwell Bullpitt ◽  
David Gartshore ◽  
William Adcock ◽  
T. C. Khor ◽  
...  

1975 ◽  
Vol 53 (4) ◽  
pp. 596-603 ◽  
Author(s):  
Roderick E. Wasylishen ◽  
Thomas R. Clem ◽  
Edwin D. Becker

Carbon-13 and proton chemical shifts have been measured for several monosubstituted isothiazoles. Substituent effects upon these chemical shifts are compared with those observed for monosubstituted benzenes, pyridines, and thiophenes. In general the observed substituent effects in the isothiazoles and thiophenes closely parallel one another. Correlations between the observed carbon-13 Chemical shifts and CNDO/2 calculated charge densities are examined.


1969 ◽  
Vol 47 (1) ◽  
pp. 1-17 ◽  
Author(s):  
L. D. Hall ◽  
J. F. Manville ◽  
N. S. Bhacca

A detailed study has been made of both the 1H and 19F nuclear magnetic resonance (n.m.r.) spectra of a series of hexopyranosyl fluoride derivatives. Some of the 1H spectra were measured at 220 MHz. The 1H spectral parameters define both the configuration and the conformation of each of these derivatives. Study of the 19F n.m.r. parameters revealed several stereospecific dependencies. The 19F chemical shifts depend upon, (a) the orientation of the fluorine substituent with respect to the pyranose ring and, (b) the relative orientation of other substituents attached to the ring; for acetoxy substituents, these configurational dependencies appear to be additive. The vicinal19F–1H coupling constants exhibit a marked angular dependence for which Jtrans = ca. 24 Hz whilst Jgauche = 1.0 to 1.5 Hz for [Formula: see text] and 7.5 to 12.6 Hz for [Formula: see text] The geminal19F–1H couplings depend on the orientation of the substituent at C-2; when this substituent is equatorial JF,H is ca. 53.5 Hz and when it is axial the value is ca. 49 Hz.


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