Introducing thienobelts: Structure and electronic properties of belt-shaped thienoacenes

Thiophene plays a fundamental role in the development of semiconducting materials for organic electronics. In this work, we introduce a novel class of thiophene-based compounds, namely thienobelts, which are obtained by wrapping up linear thienoacenes into belt-shaped structures. Ab-initio calculations are used to provide preliminary insights into their structural and electronic properties. We find that belt-shaping significantly impacts these properties with respect to those calculated for their linear counterparts. Our analysis suggests that thienobelts can be classified as organic semiconductors, but also reveals significant differences among them. Small thienobelts are aromatic and characterized by poor optical absorption properties, whereas large thienobelts display the opposite behavior. Based on this outcome, we identify two compounds that may deserve attention as synthetic targets.