p-Fluorphenyl group as an indicator of charge on the carbon atom in aromatic compounds

A linear equation is presented for determining, from the chemical shift of¹⁹F in a p-fluorophenyl group, the effective charge of that CH fragment of the original aromatic molecule the carbon atom of which is bonded to the fluorophenyl indicator group. It has been shown that for a cyclic aromatic 6-electron system determination of the effective charges of the CH fragments by quantum-chemical calculations and the evaluation of this charge from the¹⁹F chemical shift of the corresponding p-fluorophenyl substituents lead to coincident results.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2219–2222, October, 1989.The authors are grateful to N. P. Gambaryan for fruitful discussions.