Abstract The synthesis and properties of novel cyanine and ketocyanine dyes incorporating 9, 9-di-n-propylfluorenyl units is reported. While bathochromic shifts of order 100 nm are observed in cyanines for addition of each vinylene unit (lengthening the methine chain) it was observed that addition of the fluorenyl unit enabled fine tuning of the UV–visible absorption spectrum. The hypsochromic shift in the UV–visible absorption spectrum of the ...
