Functional Perylene Dyes:Synthesis,Optical And Aggregation Behaviors

In this thesis,unsymmetrically substituted amphiphilic perylene bisimide dyes were designed and synthesized and their optical behavior and supramolecular self-assembly were investigated.The novel dyes contain perylene/pyrene bischromophores,which leads to an intramolecular fluorescence resonance energy transfer phenomenon.And unsymmetrically substituted amphiphilic perylene bisimide derivative with perylene/pyrene bischromophores was fully characterized.Two synthesis strategies of one-pot and two-step methods,three synthesis routes were adopted,and the optimized synthesis route was determined with simple purification and yield of 42%.The optical behaviors of these functional dyes were studied by UV/Vis absorption and fluorescence emission spectroscopy.These dyes are highly fluorescent and cover the whole visible region.The absorption and emission spectra of donor/acceptor dyes showed that the intramolecular fluorescence resonance energy transfer efficiency from pyrene to perylene bisimide chromophore occurres with the efficiency as high as 96.4%,which results in high sensitivity of fluorescence color to environmental polarity.Under the irradiation of 365 nm ultraviolet lamp,as the polarity of the solvent increases,the fluorescence color of the donor/acceptor dyes changes from green to yellow,which demonstrates its application potential as a novel fluorescent resonance energy transfer probe.UV/Vis absorption and fluorescence spectroscopy were used to study the aggregation behavior of dyes in organic solvents and water.The spectra showed that dyes aggregated in water and tetrahydrofuran solution of high concentration.Dynamic light scattering and transmission electron microscopy were used to study the aggregation behavior of dyes in water.It was observed that donor/acceptor dyes in water assembled into bilayer vesicles with narrow size distribution through hydrophobic effect and π-π interaction.The 3D fluorescence spectra showed that these vesicle aggregates in water emit fluorescence at a wavelength of 650-850 nm in the near infrared region.