Synthesis and electronic properties of dibenzothieno-isoindole dione building blocks for organic electronic devices

Abstract

The ability to control the physical and electronic properties of conjugated polymers and small molecules has led to considerable focus on developing new electron-accepting (EA) and electron-donating (ED) building blocks, which are essential for obtaining new and efficient organic electronic materials. This work involves the design, synthesis and characterization of fused thieno-isoindole scaffolds as versatile electronic building blocks. The advantages of the dibenzothieno-isoindole dione scaffold include the potential for a concise, 3-step synthetic route from easily available starting materials and the capacity to fine-tune physical, optical, and electronic properties via numerous synthetic handles. A short efficient synthesis to dibenzothieno-isoindole dione derivatives was therefore developed from commercially available starting materials. Two steps are required; a Suzuki-Miyaura coupling followed by an oxidative cyclization. The synthesis of several dibenzothieno-isoindole dione derivatives will be discussed as well as structure activity relationships, solid-state structure, and physicochemical properties. The investigation of noncovalent interactions involving halogens has led to the discovery of numerous reliable motifs for supramolecular design. Four isomers of diiodo-xylene were synthesized and their single crystal X-ray structures determined. I⋯I interactions were found to play a strong role in defining the crystal packing patterns of these simple aromatic structures.