Iptycene-Containing Azaacenes with Tunable Luminescence

Abstract

An optimized route toward iptycene-capped, p-dibromo-quinoxalinophenazine was developed, increasing the yield significantly from literature procedures. New iptycene-containing symmetrical aza­acenes were synthesized from this intermediate using Suzuki–Miyaura cross-coupling, and their photophysical properties were evaluated. Tuning the substituents allows modulating emission wavelengths across the visible spectrum. Substitution with 3-methoxy-2-methylthiophene exhibits a quantum yield of 35%. The (triisopropylsilyl)acetylene product has a quantum yield of 38% and serves as a model compound for the synthesis of polymers based on this electrooptically active molecular motif. Keywords: N-heteroiptycene - Suzuki–Miyaura cross-coupling - Sonogashira coupling - pyrazinoquinoxaline - luminescence