Chemical shifts and coupling constants in pentafluorophenyl derivatives. I. Correlations of chemical shifts, coupling constants, and .pi.-electronic interactions

The fluorine chemical shifts and coupling constants of 61 pentafluorophenyl derivatives with widely varied substituents are examined. It is found that two of the meta coupling constants form good straight line relationships with the chemical shift of the p-fluorine and it is argued that these relationships are mainly dependent upon the pi-electron donor or acceptor character of the substituent. (Author)