Synthesis and optical properties of cyanine dyes with an aromatic azonia skeleton

Abstract

Six cyanine dyes with an aromatic azonia skeleton (1a–f) were obtained by the reaction of chlorinated heptamethylene cyanine and 2-aminopyridine derivatives. Five of them (1a–d and 1f) emit red and near-infrared fluorescence at 600–800 nm. The fluorescent stains of living cells indicate that they can penetrate the cell membrane, especially the hydroxyl-substituted dye (1c), it has lysosome targeting ability.