ELECTRONIC EFFECT OF THE TRICYANOMETHYL GROUP BY C-13-NMR AND F-19-NMR - NATURE OF ARYL F-19-NMR POLAR FIELD EFFECTS IN THE BENZENE AND NAPHTHALENE RING-SYSTEMS

A number of tricyanomethyl-substituted aryl derivatives (phenyl, 1-and 2-naphthyl, 1-and 2-fluoronaphthyl), l-phenyl-4-(tricyanomethyl)bicyclo[2.2.2]octane, and several ammonio-substituted fluorophenyl and fluoronaphthyl derivatives have been synthesized and their 19F and 13C NMR chemical shifts have been measured. An analysis of the data provided the following information. (1) Definitive substituent parameters (and °) for the C(CN)3 group. (2) An unambiguous delineation of polar aryl 19F NMR substituent chemical shifts (SCS) in the benzene and naphthalene ring system into direct field (FD) and field-induced polarization (FT) contributions. (3) Experimental support for the overall validity of the dual substituent parameter (DSP) equation to dissect 13C and 19F SCS into polar and resonance effect contributions. (4) The effective dielectric constant term is a significant parameter determining solvent trends for polar 19F SCS of the C(CN)3 group. © 1979, American Chemical Society. All rights reserved. © 1979, American Chemical Society. All rights reserved.