The ultraviolet absorption spectra of some chlorinated biphenyls. Academic Article uri icon

abstract

  • The UV spectra of 29 chlorobiphenyls have been examined. With increasing chloro substitution in which there are less than two chlorine groups ortho to the Ph-Ph bond the lambdamax values for the K band (attributed to the conjugation between the two phenyl rings) are shifted to longer wavelengths and for the more highly substituted chlorobiphenyls there is also a bathochromic shift of the main band (due to the benzenoid skeleton). Introduction of two or more chlorine atoms ortho to the Ph-Ph bond results in a hipsochromic shift of K band and diminished xi value due to steric inhibition of resonance between the two phenyl rings. The sterically hindered chlorobiphenyls and the more highly chlorinated Aroclors also exhibit a series of low-intensity fine-structured absorption maxima between 268-302 nm. The UV spectra of chlor-biphenyls are particularly diagnostic with respect to the degree of substitution at the 2, 2', 6 and 6' positions and can be used in the structural analysis of separated chlorobiphenyls. The data may also aid in correlating the photochemical reactivities.

published proceedings

  • Bull Environ Contam Toxicol

author list (cited authors)

  • MacNeil, J. D., Safe, S., & Hutzinger, O.

citation count

  • 19

complete list of authors

  • MacNeil, JD||Safe, S||Hutzinger, O

publication date

  • January 1976