Verdazyls. Part 30. N-1,N-1′-linked biverdazyls (bis-1,2,3,4-tetrahydro-s-tetrazin-1-yls) with a [2.2]paracyclophanylene bridge
Three isomeric biverdazyls (3b–d) containing a [2.2]paracyclophanylene bridge have been prepared. The zero-field splitting parameter |D′| could be evaluated from the e.s.r. spectra taken in liquid crystalline solution. The e.s.r. and n.m.r. results of (3b–d), which indicate RT|J|aN, are discussed with respect to the structure and the distortion about the N–bridge bond.