Optical, Electrochemical and Thermoanalytical Investigations on Newly-Synthesized Perylene-3,4,9,10-Dianhydride Fluorescent Dyes.

A series of dyes using tetrachloroperylene dianhydride as fluorescent chromophore was synthesized by the substitution of suitable aliphatic and alicyclic alcohols in alkaline medium, and evaluation of dyes was done for their optical, electrochemical and thermal properties. These dyes exhibited absorption maxima λmax in the range of 440-460 nm in aqueous medium due to the presence of highly-conjugated framework. Fluorescence spectra of these dyes in water showed sharp emission peaks with small bandwidths and large fluorescence rate constants, i e., 1.36 × 10(8) to 2.25 × 10(8) S(-1). Redox potential E1/2 and band gap energy Eg were observed in the range of -0.689 to -0.784 and 2.530 to 2.610 eV, respectively. Thermal stability was noticed up to 300 °C on the basis of TG and DTA findings. The structures of perylene-azo dyes were confirmed by FTIR and NMR spectroscopy. Graphical Abstract Optical, electrochemical and thermoanalytical investigations on newly-synthesized perylene-3,4,9,10-dianhydride fluorescent dyes.