Streamlined Access to Substituted Benzothieno-S,S-Dioxide-Benzofuran (BTOBF): Properties and Application in Solution-Processed Organic Light-Emitting Diodes

Abstract

Utilizing a streamlined five-step synthesis process, we have successfully produced a diverse set of adjustable benzo [4,5]thieno-S,S-dioxide-[3,2-b]benzofurans-based compounds via Michael's addition−elimination reaction, Suzuki-Miyaura coupling, and intramolecular oxidative C−H/C−H coupling, in 70−90% yields. The synthetic strategy employed demonstrates that the compounds can be modified on either side by introducing various types of groups at positions 2 and 3, with the possibility of extending the aromatic portion in place of benzofuran. Thus, these compounds exhibit a distinctive dual-state emission, showcasing very good quantum yields up to 63% in the solid state and 83% in solution. Additionally, these compounds were integrated into ambient conditions and solution-processed, nondoped OLEDs, demonstrating promising results with a luminance of 850 cd/m 2 and a turn-on voltage of 3.50 V.