Photoactively electroactive polyamide with azo group in the main chain via oxidative coupling polymerization

Abstract

In this work, a simultaneously photoactive and electroactive polyamide exhibiting interesting spectroscopic and electrochemical properties was prepared. Firstly, a 4-aminoazobenzene-capped amide oligomer (ACAO) was synthesized and characterized by ¹H NMR, ¹³C NMR and mass spectroscopy. Subsequently, the photoactively electroactive polyamide was synthesized through reacting ACAO with p-phenylenediamine by oxidative coupling polymerization, followed by characterization with GPC and ¹H NMR. After alternate irradiation with UV and visible light, the azobenzene exhibited obvious photoelectrochemical switching properties. The reversible photoisomerization (i.e., cis ↔ trans) behaviour of the backbone azobenzene moieties in the as-prepared photoactively electroactive polyamide was analyzed by in situ monitoring through systematic studies of UV-visible and ¹H NMR spectroscopies. On the other hand, the electrochemical activity (i.e., redox capability) of the as-prepared polyamide was explored by cyclic voltammetry (CV) measurements.