LIGHT ABSORPTION STUDIES: PART XVII. THE ULTRAVIOLET ABSORPTION SPECTRA OF CHLOROBENZENES

Abstract

The ultraviolet absorption spectra of a series of chlorobenzenes are determined. The spectral data suggest that the apparent mesomeric effect of the chlorine atom is greater than that of the fluorine atom, that solvent–solute interactions are generally less important in chlorobenzenes than in fluorobenzenes, and that, as expected, the effective interference radius of the chlorine atom is large. Moreover, spectral changes in o-substituted chlorobenzenes are consistent with the assumption that maximum electronic interaction requires the chlorine atom to be in the same plane as the benzene ring. The conformations of o-chloroacetophenone and o-chlorophenol are briefly discussed.