LIGHT ABSORPTION STUDIES: PART VIII. THE SECONDARY BAND OF ACETOPHENONES AND BENZOIC ACIDS IN ULTRAVIOLET SPECTRA

Abstract

The absorption spectra of some acetophenones and benzoic acids have been measured in different solvents in the region 220–400 mμ. The two major bands are compared and it is found that steric interactions which considerably alter the high-intensity band have less and somewhat different effects on the secondary band. Solvent effects and the changes observed on substitution indicate that the weaker band (C-band) is essentially of similar character to the high intensity primary band (B-band). A unifying hypothesis to account for the observed changes is presented.