Near-infrared electrochromic and chiroptical switching polymers: synthesis and characterization of helical poly(N-propargylamides) carrying anthraquinone imide moieties in side chains

Abstract

Optically active poly(N-propargylamides) containing chiral anthraquinone imide (AQI) side groups have been synthesized. The chiroptical and electrochromic properties of the polymers are investigated. The polymers exhibit intense Cotton effects in the absorption regions of both main- and side-chains, strongly suggesting a helical conformation of the polymer backbone and a skewed packing of pendant chromophores. Additionally, the polymers show two reversible redox states (radical anion and dianion). Intense circular dichroism (CD) signals centered at 780 nm and 530 nm are assigned to the radical anion and dianion intermediates, respectively. The voltage-controlled reversible Cotton effects demonstrate the newly synthesized AQI-containing poly(N-propargylamides) as potential electrochemically driven chiroptical switching materials that operate in the near-infrared wavelength region.