Construction of rylene near-infrared absorption dyes with azaperylene monoimide

Abstract Rylene NIR absorption dyes APMI-N (λmax = 796 nm) and (APMI-K, λmax = 787 nm) with compact conjugation, and excellent solubility, were designed and synthesized. Acid/base sensitive dyes 3, 4, 6, and 7 were obtained as well. Their maximum absorption could be adjusted conveniently from 532 nm to 715 nm by adding acid or base in the solvent. Theoretical simulations indicate both protonation of carbonyl O and electron donating O− in perylene monoimide play a critical role in absorption changing of those dyes.