A highly fluorescent PN-heterocycle-fused pyrene derivative with strong self-dimerisation through hydrogen bonding

The pyrene moiety has been utilised in a variety of systems that exhibit either 'turn on' or 'turn off' fluorescence in response to specific analytes. Continued development of hydrogen bonding pyrene-containing scaffolds seeks to establish a wider substrate scope and utility of these hosts. Herein, we report one such example in the form of a pyrene-containing phosphaquinolinone. This molecule exhibits both strong dimerisation in the solution state and pi-pi stacking within the pyrene backbone in the solid state. Further, it shows an enhanced quantum yield (70%) and a large extinction coefficient compared to its parent framework.