Synthesis And Multi-Stimuli-Responsive Self-Assembly Of Rod-Coil Molecules Incorporating Bispyridyl Group

Pyridine is a six-membered heterocyclic compound containing N atom.Pyridines,as a class of compounds that respond to multiple stimuli,have received extensive attention in the synthesis of complexes.Pyridine compounds can form multifunctional complexes with various configurations and unique properties with most metal ions and acids.Pyridines have broad application prospects in the fields of selective catalysis,anticancer drugs,molecular devices,and molecular recognition due to their diverse coordination,self-assembly modes and multiple stimuli responses.Bispyridyl rigid rod-coil molecules combine the multi-stimuli responsiveness of pyridyl and the easy assembly property of rod-coil molecules,so that multi-stimuli-responsive supramolecular assembly complexes can be prepared simply and rapidly.In this thesis,a number of bispyridyl rod-coil molecules were designed and synthesized,and characterized by ~1H NMR and MALDI-TOF MS.Using UV-Vis spectrophotometer,fluorescence spectrophotometer,atomic force microscope,transmission electron microscope,circular dichroism spectrometer,infrared spectrometer and other instruments,the influence of different flexible side chains of bispyridyl molecules on molecular assembly,bispyridyl molecular metal complex assembly,bispyridyl molecular carboxylate assembly and co-assembly of bispyridyl molecules with other rod-coil molecules was investigated.By changing the flexible chain of bispyridyl molecules,bispyridyl molecules can be assembled into spherical,sheet,fiber and other structures in aqueous solution.By coordinating with metals,bispyridyl molecules can obtain polymer materials such as complex metal gels and films,and can also be assembled into fibers,sheets and network structures in aqueous solutions.Bispyridyl molecules can form salts with tetrafluoroterephthalic acid,and then pyridinium salts and acid ions co-assemble into fiber,network and other structures in aqueous solution.Bispyridyl molecules can be co-assembled with other rod-coil molecules in aqueous solution,and their morphology and size can be precisely regulated according to the different co-assembled molecules.The morphology control of amphiphilic rod-coil molecules based on bispyridyl groups is more abundant than the stimulus response of general rod-coil molecules,because bispyridyl groups can coordinate or form salts with metals and organic acids to generate corresponding morphology.These nanoaggregates can induce the change of morphology and physical properties of molecules,which were suitable application in field of the organic smart soft materials.The results obtained in this thesis will provide a solid theoretical basis for the development of stimuli-responsive rod-coil supramolecular materials.