Although thiophene-based materials are among the most widely studied conjugated materials for a number of technological applications, most discussions of emissive conjugated materials have focused on other systems, primarily due to the lower emission quantum yields of thiophene-based systems. Over the last decade, however, this has begun to change with the development of new highly emissive thiophene-based materials. In this review, we provide an overview of fluorescent thiophene-based materials and their applications, highlighting in particular the various methods employed to achieve highly emissive materials, as well as a variety of reported applications including fluorescent biomarkers and organic light emitting diodes.

New synthetic methods have been developed for the preparation of 4-alkyl- and 4-aryl-pyrrolo[2,3-d:5,4-d']bisthiazole (PBTz) building blocks from 2,4-thiazolidinedione. The resulting PBTz products have been fully characterized via structural, electronic, and optical methods, thus allowing full comparison to the previously reported dithieno[3,2-b:2',3'-d]pyrrole (DTP) analogues. Such comparisons then allow a detailed discussion of the relative electronic effects of the various methods utilized to tune the properties of the parent DTP building block.