Non-aryl substituted aza-BODIPYs at 1,7- or 3,5-sites: synthesis, structures, optical properties, and applications

Abstract

Aza-borondipyrromethenes (aza-BODIPYs) possess excellent photophysical properties, and the structurally modified dyes exhibit favourable performance and applications in biomolecular sensing, photoelectric materials, and tumor phototherapy. Therefore, the design of aza-BODIPYs with innovative structures is the foundation for exploiting intelligent applications. However, the current modified methods are mainly focused on aryl-substitutions at 1,7,3,5-sites in the aza-BODIPY system, and there are few reports on non-aryl substituted aza-BODIPYs. Non-aryl substitutions exhibit significant performance, such as increased water-solubility, reduced molecular weight, and promoted non-radiative transitions by rotation of the substituent, as well as potential unknown optical manifestations that are explored. Herein, the structures and applications of non-aryl substituted aza-BODIPYs at 1,7- or 3,5-sites are reviewed for the first time, and further design strategies and application prospects are discovered, considering them as a reference for the aza-BODIPY system.