ABSTRACT
Due to the widespread occurrence of polychlorinated biphenyls in the environment, there has been considerable interest in the spectroscopic properties of these compounds. The UV spectra of biphenyl and several substituted biphenyls have been the subject of a number of investigations. The former band is generally referred to as the "main band". For the monochlorobiphenyls, the main absorption band was only slightly changed in comparison to biphenyl. Inspection of the UV spectra of the more highly substituted chlorinated biphenyl isomers revealed a number of useful correlations. Moreover the extinction coefficients of the band maxima for the biphenyl derivative were two to three times greater than those observed for the trichlorobenzene isomer indicating that the absorption is nearly additive for the two benzene rings of the biphenyl derivative. Similar results have been obtained with highly hindered alkyl biphenyls.
