A facile strategy for π-extended BOPYINs: transformation into six-membered BODIPY analogues and their optical properties

Two novel π-extended BOPYIN cores and their derivatives (10a-10e) were prepared, exhibiting significant red-shifts <i>vs.</i> conventional BOPYINs and BODIPY derivatives in optical spectra. Notably, condensation product 5 and BOPYIN derivatives selectively converted to a six-membered BODIPY analogue (11). Furthermore, grinding can repeatedly light up the solid-state fluorescence of compound 7.