Spectroscopic and electrochemical behavior of newly synthesized high fluorescent symmetric 4'-nitrophenyl-3,4,9,10-perylenebisdiimide-azo hybrid dyes.

The investigation has been made in the synthesis of azo hybrid rylene dyes. The hybridization of perylene bis-diimide with phenolic azo-dyes was carried out by the nucleophilic substitution (SNAr) reaction of tetrachloroperylene-3,4,9,10-bisdiimide 3 with phenolic azo-dyes 4a-g in basic medium. The hybrid dyes exhibited two absorption maxima λmax in the range 300-350, 426-438 nm in ethanol due to presence of azo linkage and highly conjugated framework of π bonds. Fluorescence spectra of these dyes in water showed sharp emission peaks with small bandwidths in the range 490-495 nm, and fluorescence quantum yield was 0.71-0.83 in comparison with standard reference fluorescein. The structures of perylene-azo dyes were elucidated by FTIR and NMR spectroscopy. Luminescence was determined by LS-100 meter which was found to be excellent in limits 0.208-0.239 cd/m(2). Cyclic voltammetric studies were made by Electrochemical Analyzer CH1830C which showed the oxidation chemical potential of these hybrid dyes.