New near-infrared indocyanines and their spectral properties in SiO_2 sol-gel

摘要

Near-infrared dyes are becoming more and more important in modern technologies.To improve the stability and spectral properties,new heptamethine 3H-indocyanine dyes were synthesized and tested in solvents and SiO_2 sol-gel.The results show that the dyes containing cyclohexenylene bridge and N-(4-carboxy) benzyl groups have better photo-stability and longer absorption wavelength than those containing linear heptamethine bridge and/or N-(5-carboxy)-pentanyl groups.The absorption maxima are in reverse proportion to the polarity of the solvents.When dyes doped in SiO_2 sol-gel,the absorption maxima are between their relative ones in methanol and in DMF.