Calculations of chemical shifts

The use of electric field theory to predict the chemical shifts of fluorine nuclei in molecules containing localized double bonds has been justified in a previous publication [1]. This approach is extended to a series of substituted cyclohexenes undergoing rapid conformational interconversion. No direct experimental investigation of the geometry of these molecules has been reported but the calculations have been performed for two theoretical models and a further one in which the system is completely strain-free. It is shown that whereas no real distinction may be drawn between the two theoretical models, the unstrained system is totally unrepresentative of the facts.