Efficient Spin-Doublet Near-Infrared Emission Beyond 800 nm via Intramolecular Charge Transfer in Quasi-Planar Donor-Acceptor Structure

Abstract

Donor–acceptor type near-infrared luminescent radicals were synthesized with high yields via an iodinated building block. Rigid quasi-planar configuration promotes the formation of an intramolecular charge-transfer excited state with non-bonding characteristics. This ultimately leads to efficient deep-NIR emission beyond 800 nm, realizing a photoluminescence quantum efficiency as high as 21%.