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 λmax values for the κ band (attributed to 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 κ band and diminished e{open} 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 finestructured absorption maxima between 268-302 nm. The UV spectra of chlorobiphenyls 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.
Original language | English (US) |
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Pages (from-to) | 66-77 |
Number of pages | 12 |
Journal | Bulletin of Environmental Contamination and Toxicology |
Volume | 15 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1976 |
ASJC Scopus subject areas
- Toxicology
- Pollution
- Health, Toxicology and Mutagenesis