Novel Fluorescent Characters of Tetrabenzofluorene Bearing p-Nitrophenyl Groups

Abstract

The Suzuki-Miyaura coupling of 3,14-dibromo-17,17-dialkyltetrabenzofluorene with arylborates (p-X-C₆H₄B(OH)₂; X = H, -OCH₃,NMe₂, -NO₂) in the presence of Pd(PPh₃)₄ as a catalyst afforded corresponding 3,14-diaryl derivatives in moderate to good yields. These compounds show intense blue to yellow fluorescence with large quantum yields in solution and moderate quantum yields in the solid states. In particular, the dinitro derivative exhibits considerably large solvent effect over 90 nm and the aggregation-induced emission (AIE) effect in aqueous THF (>70%) solutions.