Association in Biradical Solutions

Publisher Website
Google Scholar
Abstract
The effects of temperature and optical irradiation upon the intensity of the electron paramagnetic resonance of Chichibabin's hydrocarbon [4,4′‐bis(diphenylmethyl)biphenyl] and related compounds have been studied. Relative intensities were determined by employing a field modulation amplitude sufficient to remove all structure and measuring first moments of the resultant derivative spectrum. It has been found that the room‐temperature intensity can be maintained at low temperatures if the specimen is cooled rapidly enough. Further, the intensity can be enhanced by optical irradiation at —100°C. These effects are reversible, but a number of related irreversible effects also occur. The results suggest that the observable paramagnetic species in biradical solutions is a dimer or higher polymer of Chichibabin's hydrocarbon. As a result, the interaction between the unpaired electrons of the biradical is much smaller than would be expected for a monomer.

This publication has 16 references indexed in Scilit: