tert-Butyl substituted aza-BODIPY-based bromides for phototherapy

Asymmetric mono - and dibromides aza-BODIPYs at 6-site were prepared. The singlet oxygen yield of monobromide MBr-azaBDP with the direct attachment of the –Br group at 6-site was higher than that of vinyl dibromide DBr-azaBDP. Self-assembled MBr-azaBDP-NPs with laser irradiation possessed a photothermal conversion capability. Monobromide MBr-azaBDP was discovered to be an effective PDT-PTT combined therapeutic agent and prospective candidate for tumor phototherapy by integrating tert-butyl free rotation and halogen substitution. However, comparing to MBr-azaBDP, DBr-azaBDP as a fluorescent dye possesses narrower full width at half maxima, higher molar extinction coefficient and fluorescence quantum yield.