Triptycene End-Capped Benzothienobenzothiophene and Napthothienobenzothiophene.

: Previously it was demonstrated that triptycene end-capping can be used as a crystal engineering strategy to direct the packing of quinoxalinophenanthrophenazines (QPPs) towards cofacially stacked π dimers with large molecular overlap resulting in high charge transfer integrals. Remarkably, this packing motif was formed under different crystallization conditions and with a variety of derivatives bearing additional functional groups or aromatic substituents. Benzothienobenzothiophene (BTBT) and derivatives thereof are known as some of the best performing compounds for organic field-effect transistors. Here we introduce the triptycene end-capping concept to this class of compounds and investigate polymorphic crystal structures to evaluate the potential of triptycene end-caps as synthons for crystal-engineering.