Solution-processable conjugated polymers containing alternating 1-alkyl-1,2,4-triazole and NSN links

Abstract

Poly(sulfur nitride), [SN]x, is an infinite π-bonded system and only known polymeric superconductor composed of nonmetallic elements. The appealing electronic properties of [SN]x, along with the safety issue involved in the synthesis, have motivated research on [SN]x analogues, for example, conjugated polymers consisting of sulfur–nitrogen moieties separated by heterocyclic groups. In this paper, we report an exploration for a new NSN-linked polymer, with a major objective to improve its solubility for low-cost, large-area fabrication of molecular devices based on a solution process. Specifically, we present the synthesis and characterization of a conjugated polymer based on alternating 1-alkyl-1,2,4-triazole and sulfur–nitrogen. We found that 4-dimethylamino pyridine is an effective catalyst for the polymerization of bis-N-sulfinyl-3,5-diamino-1-dodecyl-1,2,4-triazole, resulting in polymers that show a broad absorption band in the range of 400 to 600 nm. Moreover, this polymer exhibits high solubility in a variety of non-polar solvents, including tetrahydrofuran, chloroform, dichloromethane, and chlorobenzene.