Modular synthesis and photophysical and electrochemical properties of 2,3,5,6‐tetraaryl‐substituted benzo[1,2‐b:5,4‐b′]difurans

Abstract

AbstractWe developed a versatile synthesis of tetraaryl‐substituted benzo[1,2‐b:5,4‐b′]difurans (m‐BDFs) via a zinc‐mediated intramolecular double cyclization reaction of 4,6‐bis(phenylethynyl)‐1,3‐benzenediol, followed by a palladium‐catalyzed cross‐coupling reaction. In comparison with the corresponding benzo[1,2‐b:4,5‐b′]difuran (p‐BDF) isomers reported previously, the m‐BDFs are slightly wider between HOMO and LUMO, as well as a lower energy level of the former. These differences in properties between the structural isomers can be ascribed to the difference in the conjugation type. The compounds had high charge carrier mobility up to 1 × 10−3 cm2/Vs, which makes them attractive materials for organoelectronics applications. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:316–324, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20682