Indo study of the angular dependences of isotropic hyperfese interaction constants in the model conformations of the nitrobenzene radical anion

Abstract

The UHF/INDO calculations of the model conformations of the nitrobenzene radical onion show that rotation of the nitro group relative to the plane of the benzene ring is accompanied by a pyramidal distortion of the group caused by the pseudo-Jahn-Teller effect (vibronic interaction between the ground n and totally symmetric lowest excited σ states). The angular dependences of the14N,13C,1H, and17O Isotropic hyperfine interaction constants are analyzed. Experimental ESR data are interpreted for the radical anions of nitrobenzene derivatives with ortho-alkyl groups.