Investigations on the Synthesis, Reactivity, and Properties of Perfluoro‐α‐Benzo‐Fused BOPHY Fluorophores.

The synthesis and reactivity of 3,8‐dibromo‐dodecafluoro‐benzo‐fused BOPHY 2 are reported, via SNAr with O‐, N‐ S‐ and C‐nucleophiles, and in Pd(0)‐catalyzed cross‐coupling reactions (Suzuki and Stille). The resulting perfluoro‐BOPHY derivatives were investigated for their reactivity in the presence of various nucleophiles. BOPHY 3 displays reversible color change and fluorescence quenching in the presence of bases (Et3N, DBU), whereas BOPHY 7 reacts preferentially at the α‐pyrrolic positions, and BOPHY 8 undergoes regioselective fluorine substitution in the presence of thiols. The structural and electronic features of the fluorinated BOPHYs were studied by TD‐DFT computations. In addition, their spectroscopic and cellular properties were investigated; BOPHY 10 shows the most red‐shifted absorption/emission (λmax 659/699 nm) and 7 the highest fluorescence (Φf=0.95), while all compounds studied showed low cytotoxicity toward human HEp2 cells and were efficiently internalized. [ABSTRACT FROM AUTHOR]