Synthesis Of Amphiphilic Near Infrared Dyes And Modulation Of Supramolecular Polymerization Properties

In recent years,aza-BODIPY functional molecules have been widely used as nearinfrared dyes in cutting-edge fields such as biological probes,photothermal therapy and solar cells.In this thesis,a series of novel amphiphilic aza-BODIPY dyes have been synthesized and studies on the modulation of supramolecular polymerization of these dyes have been carried out.In this thesis,four amphiphilic near-infrared dyes Aza-BODIPY 1a,b and 2a,b bearing amide-triazole structural unit were designed and synthesized.Further supramolecular polymerization studies were carried out on Aza-BODIPY 1a and 2b.Aza-BODIPY 1a formed H-aggregates(Agg.I)with a large blue shift in the absorption spectra in methanol and another aggregate with a broader absorption spectra in water(Agg.II).The modulation of supramolecular polymerization properties were further studied in mixed solvent of methanol/water.The results revealed that Agg.II could be obtained via the cooling of the hot solution,and the Agg.II could be transformed into Agg.I upon ultrasonication or living supramolecular polymerization.The thermodynamic and kinetic properties of the supramolecular polymerization for Agg.I and Agg.II were systematically studied at three different water/methanol ratios.The modulation of the living supramolecular polymerization for the transformation from Agg.II to Agg.I was further achieved by the seed-induced method.The thesis further studied the supramolecular polymerization properties of AzaBODIPY 2b in water.The results revealed that Aza-BODIPY 2b could self-assemble into three types of aggregates,of which Agg.I was thermodynamically stable aggregates,Agg.II was kinetically controlled metastable aggregates and Agg.III were new aggregates obtained by heating the solution.The thermodynamic and kinetic properties in the supramolecular polymerization process were studied systematically in water and the morphology of the three aggregates were further characterized.A series of amphiphilic near-infrared aza-BODIPY dyes have been synthesized through rational molecular design in this thesis,and the supramolecular polymerization properties of the dye molecules have been studied systematically.The results of the thesis can provide valuable strategies for modulating the aggregation properties of amphiphilic dyes as well as the living supramolecular polymerization.