Conjugated Macromolecules. Stellate Structure Based On The Core - Arm / The Hyperbranched Conjugated The Design, Synthesis And Properties Of The Polymer

With the development of information technology,the whole human society is showing more and more new phenomena.In the field of Photoelectric Display,the research and applications of organic and organic/inorganic hybrid optoelectronic materials and devices have made significant progress and development.In the same time,organic materials,with the merits such as fast-response,high-density,low-cost and so on,has become one of the rising new generations of optoelectronic materials. Among them,two kinds of materials have attracted more intention of scientists.One is the hyperbranched conjugated polymers,which possesses more merits such as excellent solubility,low viscosity,electrical performance etc,and their structures can be designed purposefully.Another is the dendritic molecules or starburst macromolecules,which size,shape,solubility,structure and layout,as well as chemical purity,and so on,can be precisely controlled in synthesis.In order to regulate the electronic-hole transporting performance or improve the photophysicai properties of material and device,one of the methods is introducing functional groups which possess light performance,mechanical or thermal stability,and so on,to optimize the structure of the materials.Based on those mentioned above,it is important in theoretical and practical value to research and develop new high-performance organic optoelectronic materials.In this paper,we have designed and synthesized three series of starburst conjugated macromolecules and two series of hyperbranched conjugated polymer,and studied some parts of their properties,and discussed the application of some compounds in electroluminescent devices preliminary.In the first part(Chapter 1),the development and progress of optoelectronic materials such as linear polyfluorene derivatives,linear poly(aryleneethynylene)s derivatives,hyperbranched conjugated polymers and starburst conjugated macromolecules,and so on,have been reviewed,from the perspective of chemical structure.After contrasting their characteristics,we showed the design ideas and the main research content for this paper.In the second part(Chapter 2,3,4),we have designed and synthesized three series of novel starburst conjugated macromolecules,in which adopted 5,5',10,10',15,15'- hexahexyltruxene as the core unit,bridged different functional groups,such as oligofluorenes,oligo(aryleneethynylene)s,perylene imide derivatives,and so on,as the arm modules by acetylene bonds.In Chapter 2,we have selected a reasonable design to introduce acetylene bond into Truxene-Oligofluorene system,successfully synthesized a series of alkyne-bridged starburst oligofluorene derivatives FnE-Trs(compounds D1-D3), studied their properties and simulated them by computer.The results showed that the introduction of acetylene bridge can be effectively regulated the optical properties of Truxene-Oligofluorene system,and influenced their thermal and electrochemical properties.The results of devices showed that the FnE-Tr materials are excellent luminous materials.The device ITO/PEDOT/F₂E-Tr(D2)/CsF/Al,which can be turned on at 4.8V,emitted sky-blue light.Its luminence efficiency can reach up to 1.75cd/A.When the current density increased from 2mA to 20mA,the device remains very stable electroluminescene.Computer-simulated results show that the introduction of acetylene bridge,which electron cloud is columned,reduced the space block between molecular functional groups.In the acetylene-bridged system,the functional groups can keep relatively free rotation,which resulted in that the conjugated electronic cloud are influenced,and then influenced on the properties of the compounds.In Chapter 3,we designed and synthesized a series of novel monodispersed starburst oligo(aryleneethynylene)s derivatives(DAEs),and studied their properties. The results show that their thermal stability,compared to the similar linear poly(fluoreneethynylene)s,were improved,and in the meantime,they inherited the optical properties of linear poly(fluoreneethynylene)s.Noticeably,the introduction of the Truxene core unit extended effective conjugate length for poly(fluoreneethynylene)s derivatives,the corresponding fluorene acetylene repeating units can be improved from 10 up to above 20,which resulted in that the properties of the starburst oligo(fluoreneethynylene)s materials were influenced.Similarly,in Chapter 4,we have successfully synthesized a novel starburst alkynyl-bridged macromolecule constructed with two kinds of functional groups,in which perylene imide structure is used as the arms and truxene structure as the core. In the macromolecule,the energy can transfer from the truxene core to the perylene imide arms effectively.In the third part(Chapter 5,6),we first reviewed the applications and synthesis of the carbazole bromides,and synthesized successfully compound 1,3,6,8-tertbromo-N-hexylcarbazole.And then,we designed and synthesized two series of hyperbranched polymers with four-arm structure based on 1,3,6,8-tertbromo-N-hexylcarbazole core.In Chapter 5,we synthesized successfully a new series of hyperbranched polyfluorenes based on 1,3,6,8-tertsubstituted N-hexylcarbozale core(HCFFs) via Suzuki polycondensation.By introducing 1,3,6,8-tertsubstituted N-hexylcarbozale core into the polyfleorene matrix,thermal stability of the hyper-branched polymers was effectively improved,the 5%weight loss temperatures(Td) ranging from 412.5-423.5℃,and the low energy long wavelength emission at 530nm can be suppressed.When the monomer ratio is 1:20:22,the resulted polymer HCFF20 possesses the best properties.The electroluminescence data indicated that the device configuration,ITO/PEDOT/HCFF20/Ba/Al,can be turned on at about 4.5V and emitting brightness reached 225cd/m² at a bias of 7.5V.In Chapter 6,we replaced part of fluorene units in polymers HCFFs matrix with bialkoxy-replaced benzene mioties,and synthesized a new series of hyperbranched poly(fluorenebenzene)s based on 1,3,6,8-tertsubstituted N-hexylcarbozale core (HCFBs) via Suzuki polycondensation.By introducing bialkoxy-replaced benzene mioties into the matrix of hyperbranched polymers to a suitable extent,the low energy long wavelength emission at 530 nm can be eliminated more effectively.Annealing spectra showed that the hyperbranched polymer HCFB20 film,in which monomer feed ratio is 1:20:22,can maintain stable fluorescence emission after annealing in air at 200℃for 120 minutes.The electroluminescence data indicated that the device configuration,ITO/PEDOT/HCFB20/Ba/Al,showed the most fluorescence emission at 434nm,which indicated hyperbranched polymer HCFB20 can be applied as promising luminescent materials.