Non-equivalence of vicinal proton–fluorine coupling constants in a CF3—CH2 group
- 1 July 1967
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Chemistry
- Vol. 45 (13), 1485-1489
- https://doi.org/10.1139/v67-241
Abstract
The proton magnetic resonance spectrum of the tetrahydropyranyl ether of 2,2,2-trifluoroethanol has been measured in several solvents and at different temperatures. Analysis of the ABX3 pattern produced by the trifluoroethyl group revealed a unique feature. Under all conditions, it was found that the vicinal coupling constants JAX and JBX had different magnitudes. This non-equivalence is interpreted as evidence that the C—HA and C—HB bonds of the trifluoroethyl group differ electronically. A possible relation between this finding and the anomeric effect is discussed. In contrast to the above results, the tetrahydropyranyl ether of ethanol showed equal vicinal proton–proton coupling constants in the ethyl group.Keywords
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