Synthesis of a Triethylene Glycol-Capped Benzo[1,2-c:4,5-c']bis[2]benzopyran-5,12-dione: A Highly Soluble Dilactone-Bridged p-Terphenyl with a Crankshaft Architecture

Abstract 3,10-Bis(triethylene glycol)benzo[1,2-c:4,5-c']bis [2] benzopyran-5,12-dione has been synthesized as an example of a dilactone-bridged p-terphenyl with a C2h crankshaft architecture that exhibits significant fluorescence. Lactone-bridged rotationally restricted p-terphenyl compounds are relatively unexplored, with the few known examples having very poor solubility and are therefore difficult to characterize and study. This superior TEG-solubilized analog has been shown to have much improved solubility, which should improve processability, and has attractive optical properties including efficient absorption in the near UV and significant emission of blue-violet light. Studies enabled by this TEG-solubilized crankshaft shaped molecule establishes that compounds with this architecture could be useful as pH-driven molecular switches with limited switching cycles or as “turn-off” sensors with instant fluorescence and UV absorption attenuation at high pH values.