Boratetrazines

Electron spectra of diaryl- and triaryl-boratetrazines have been investigated. The long-wave band is conditioned by polar π→π* - transition along the long axis of molecule. In the case of triarylsubstituted derivatives the π-electron system of aromatic substituent at carbon atom takes part in the transition. In the case of diarylsubstituted derivatives electron transition is localized to boratetrazine cycle. In boratetrazine cycle a delocalized π--electron system exists, however, in contrast to benzene derivatives, there is a considerable polarization