Near-infrared (NIR) absorption in the range of 0.75–2.5 μm is in great demand for a variety of applications but currently the majority of commercial NIR devices are based on inorganic materials due to the limited number of organic materials that are active in this range. Here we present the preparation and optical studies of a new series of stable azulene-containing NIR chromophores whose absorption can be tuned in the range of 0.6–1.7 μm. DFT calculation revealed that the protonation-induced low excitation gap was attributable to the substantial intramolecular charge transfer.