THE USE OF THE F-19 NMR-SPECTRA OF FLUOROPYRIDINES AND RELATED-COMPOUNDS TO VERIFY THE STATISTICAL SUBSTITUENT CHEMICAL-SHIFT VALUES OF FLUOROARENES

F-19 NMR data for fluorosubstituted-pyridines, -pyridazines, -pyrimidines, -pyrazines and -1,3,5-triazines has been used to verify previously published statistical substituent chemical shift (SSCS) values for fluoroarenes. The data also allowed generation of a set of structure factors for aromatic nitrogen heterocycles which allows the signals for these compounds to be predicted from the same set of SSCS values as fluoroarenes. When these values are used to predict the F-19 NMR signal positions of the nitrogen heterocycles, they give a correlation coefficient of predicted versus observed values of 0.987 with a standard deviation of 4.5 compared with 0.995 and 2.46, respectively, for the fluoroarenes.