The Question of σ Participation in the Bonding of Fluorosubstituted Arenes to Chromium Tricarbonyl. A 19F Nuclear Magnetic Resonance Investigation

Abstract

I9F n.m.r. chemical shifts of free fluoroarenes have been correlated with the Swain–Lupton field and resonance parameters. Comparison of these data with the corresponding Cr(CO)3 complexes shows little change in the transmission of mesomeric effects by para-substituents. Meta-substituents which interact primarily by a field effect have very little influence on the fluorine chemical shift in the complexes suggesting that the σ framework of the ring interacts with the chromium.