The influence of bond-polarisations on the molecular structures of halo-fluorobenzenes

Abstract

From the proton NMR spectra of oriented m-chloro- and m-iodo-fluorobenzenes, relative interproton and proton-fluorine distance-s have been obtained- A study of both the systems in two different liquid crystal solvents indicates negligible anisotropic contributions to the indirect spin-pin couplings and negligible solvent solute effects on the internuclear distances. The geometrical data derived have been interpreted in terms of polarisation of the C--H and the C--halogan bonds