In Silico Design of Molecular Precursors for Solution-Processable Organic Semiconductors: Structure and Electronic Properties of Sym-Azathio Circulenes

Thiophenyl circulenes, known as sulflowers, are considered potentially valuable candidates for the development of organic electronic devices. However, their usefulness as semiconducting materials is limited by their poor solubility in organic solvents. In this work, we attempt to overcome this limitation by partially replacing sulfur with nitrogen, which can be easily functionalized. The resulting compounds, namely sym-azathio circulenes, are characterized computationally. The values of selected structural and electronic descriptors compare satisfactorily with those of [8]sulflower, showing similar trends. In particular, our ab initio calculations suggest that sym-azathio[5]circulene preferentially behaves as a p-type semiconductor. Molecular dynamics simulations, performed on its otcyl derivative in solution and in the bulk, support the conclusion that sym-azathio circulenes may potentially provide molecular precursors for the development of solution-processable semiconductors.