Pentacyclic aromatic bislactam-based conjugated polymers: constructed by Beckmann rearrangement and application in organic field-effect transistor

Abstract

A Beckmann rearrangement was applied to construct the pentacyclic aromatic bislactam thieno[2′,3′:4,5]pyrido[2,3-g]thieno[3,2-c]quinoline-4,10(5H,11H)-dione (TPT) from diketone in two steps under mild conditions. Two conjugated polymers P1 and P2 based on the TPT unit were developed through a Stille coupling polymerization. Their photophysical and electrochemical properties were investigated. P1 exhibited a hole mobility up to 0.58 cm² V⁻¹ s⁻¹, whereas P2 showed a slightly lower mobility of 0.15 cm² V⁻¹ s⁻¹. The better device performance of P1 was attributed to the ordered molecular packing in the thin film. Our result indicates that the TPT moiety is a good building block in polymeric semiconductors and the Beckmann rearrangement is a powerful tool in constructing lactam-containing molecules for organic electronic applications.