Fluorine nuclear magnetic resonance spectra of some meta-substituted fluorobenzenes
Abstract
The 19F n.m.r. shifts relative to fluorobenzene of some 3- and 3,5-substituted fluorobenzenes have been measured for solutions in acetone and methanol. Correlation of the shifts with various substituent parameters is not good, and comparison of the 3-series with the 3,5-series shows that the effect of substituents is not additive. A correlation exists between the logarithm of the rate constants for the methoxydefluorination of some 5-substituted 3-nitro-fluorobenzenes and their 19F shifts.