title: New fluorescent symmetrically substituted perylene-3,4,9,10-dianhydride-azohybrid dyes: synthesis and spectroscopic studies.
abstract: Five phenolic azo-dyes (3a-e) were synthesized by diazo coupling of the suitably substituted anilines (1a-e) with phenol at low temperature in alkaline medium. The resulting dyes have low solubility in aqueous medium due to lack of carboxylic or sulfonic solubilizing functionalities. The hybridization of perylene dianhydride with phenolic azo-dyes was achieved by the nucleophilic aromatic substitution (SNAr) reaction of perylene-3,4,9,10-dianhydride 4 with phenolic azo-dyes 3a-e in basic medium. The hybrid dyes exhibit absorption maxima λmax in the range 440-460nm in aqueous medium due to presence of azo linkage and highly conjugated system of π bonds. Fluorescence spectra of these dyes in water show sharp emission peaks with small band widths. The structures of perylene-azo dyes were confirmed by FTIR and NMR spectroscopy.
authors.affiliation: Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan. Electronic address: asaeed@qau.edu.pk.
authors.forename: Aamer
authors.initials: A
authors.lastname: Saeed
authors.affiliation: Department of Chemistry, Quaid-I-Azam University, Islamabad 45320, Pakistan.
authors.forename: Ghulam
authors.initials: G
authors.lastname: Shabir
mesh_terms: D001391:Azo Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010569:Perylene / Q000138:chemical synthesis / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001391:Azo Compounds; D005456:Fluorescent Dyes; D010569:Perylene
keywords: Azo linkage; Fluorescence; Perylene-3,4,9,10-dianhydride; Phenolic dyes