Design,Synthesis And Properties Of Aza-Fused Conjugated Molecules

Aza-fused conjugated molecules have widely applications in organic optoelectronic devices,supramolecular self-assembled materials,and fluorescent sensors due to their good environmental and thermal stability and excellent photoelectric properties.The development of efficient synthetic methods for the preparation of novel aza-fused conjugated molecules and their polymers have attracted the attention of researchers.In this thesis,the Bischler-Napieralski cyclization is taken as a key step.A series of work has been carried out concerning the structural design,synthesis method,photophysical properties and self-assembly properties of aza-fused(macromolecules)molecules:1.In view of the limited synthesis methods and harsh reaction conditions of 1,10-phenanthroline derivatives with large π-structure,the Bischler-Napieralski cyclization was successfully extended by rational design of amide precursors and optimization of synthesis conditions.The thiophene-fused phenanthroline derivatives with a side chain of tert-butyl were prepared on the synthesis of 1,10-phenanthroline derivatives.The structure,photoelectric properties and metal ion response of the target compounds were studied.The performance turns out these compounds could be a class of potential metal ion responsive materials.The study in this part provides a new and efficient method for the preparation of 3,4,7,8 π-expanded soluble polycyclic phenanthroline derivatives which difficult to prepare through the existing methods,laying the foundation for the preparation of corresponding conjugated polymers.The photophysical properties,proton and metal ion response properties of the polymers were investigated,indicating that these conjugated polymers are expected to be an effective class of fluorescent chemical sensing materials.2.The thiophene-fused phenanthroline monomer in the first part was introduced into the conjugated polymer backbone to synthesize oil-soluble and water-soluble alternating copolymers combined with the Suzuki-Miyaura-Schluter polymerization.3.A bisamide precursor cored with pyrene was designed and synthesized.And a series of aza-fused rigid conjugated molecules were prepared by Bischler-Napieralski cyclization,which proved that this reaction is suitable for nitrogen fused with larger conjugate plane.Applying this group of large conjugated molecules to the organogel system,it was found that under the synergistic action of strong π-π stacking and van der Waals force,two linear alkyl-substituted molecules self-assemble to form supramolecules in various organic solvents.Besides,due to the presence of nitrogen atoms on the conjugated backbone,such molecules are sensitive to trifluoroacetic acid in solution,gel and solid state.4.A new type of coil-rod-coil molecules containing thiophene-fused 1,10-phenanthroline(and its analogs)as a core and alkylamides on the periphery were designed and synthesized.The self-assembly behavior of these molecules in solution was studied,and it was found that they can self-assemble into ordered lowdimensional structures in solution,and the effect of the rigid core on the selfassembled morphology was discussed.In addition,due to the presence of nitrogen atoms in the phenanthroline(and its analogs)moiety,these molecules were easy to be protonated,and their UV-vis absorption and emission spectra in solution exhibit reversible responsiveness to acids.