Delocalization Effects and Tunable Emission in a Class of Charged Cyclazines with Nitrogen on the Periphery

A new class of cyclazine analogues with periphery reminiscent of an aza[10]annulene framework, tethered internally by an sp³ carbon, is presented. In depth structure analysis based on NMR and X-ray diffraction data gave a deeper insight into the effect of electron delocalization on their structure and properties. A characteristic change in chemical shift positions suggested an aromatic ring current in these systems. Attractive emission properties in solid and solution states involving charge transfer is another highlight.