DFT Study of the Ambipolar Character of Polymers on the Basis of s‑Tetrazine and Aryl Rings

The semiconducting character of a set of polymers based on alternating s-tetrazine (Tz) and aryl (Ar) rings has been studied by means of density functional theory (DFT) calculations. This work is aimed at the study of the role that the nature of the Ar substituents exerts on the molecular structure, crystal packing and semiconducting properties of these polymers. The modeling of the crystal structures allowed to analyze the relative arrangement of the polymer chains and its influence on the charge transport efficiency. As a result, the most efficient and balanced charge transport is predicted for a polymer based on alternating units of Tz and [1,3]­thiazolo­[5,4-d]­[1,3]­thiazole. Also, its narrow band gap and small difference between electron affinity and ionization potential lead us to propose that polymer as a candidate to be an ambipolar organic semiconductor.