Design,Synthesis And Self-assembly Of Fuorene,Benzophenone And Diphenylmethane Bent-core Polycatenar Liquid Crystal Compounds

Supramolecular is a kind of complex and ordered molecular aggregates with a specific function.The liquid crystal is a compound that is found in 1888 by the botanist Friedrrich Reinitzer in Austria,which has both the periodic periodicity of the crystal and the fluidity of the liquid;as an important part of supramolecular,LC has self-healing,response and adaptability,and can be considered as a kind of self-assembly of functional supramolecular materials.The derivatives of fluorene unit as nuclear compounds have excellent optical properties and have wider application in area of aggregation in the materials,luminescent materials,ion recognition,fluorescence probe,cell imaging,solar cell,DNA detection,anticancer antibiotics,OFET,environmental protection,organic thin film transistor,crystal induced phosphorescence and blue fluorescence materials,semiconductor,LED,piezochromic,nonlinear optical materials,dendrimers functional materials,detection of explosives,organic gel etc.The introduction of fluorene unit into polycatenar liquid crystals would greatly improve the structure of the compounds,which is of guiding significance for the study of molecular self-assembly and optoelectronic materials.This paper is divided into three chapters.In the first chapter,we introduce the research background of fluorene,benzophenone,diphenylmethane and its derivatives,including research advance in liquid crystals and relevance.Firstly,the structure of molecules,the ratio of rigid to soft,the symmetry of rigid nuclei,the number and length of flexible chains have great influence on the self-assembly behavior and the stability of liquid crystalline phase.Fluorene derivatives have unique optical properties,triazole heterocycle has great influence on the liquid crystaline phase,polarity,dielectric anisotropy,geometry,pH and other properties;at present,fluorene derivatives shows mainly nematic and smectic liquid crystalline phases,very few cubic phase and complex 2D column.Design and synthesis new organic photoelectric liquid crystalline materials with more superior and more extensive application are of significant.The second chapter introduces the synthesis,optical properties and molecular self-assembly of,fluorenone,benzophenone,diphenylmethane polycatenar bent core liquid crystals.In this chapter,by using Wittig reaction,Suzuki reaction and Click reaction as key steps,polycatencar compounds with diphenylmethane,benzophenone,,9,9'-(dihexyl)fluorene,fluorenone,9-(dicyanomethylene)flourene,2-(diphenylmethylene)malononitrile,diphenyl sulfone as core respectively have been designed and synthesized.Their liquid crystalline preoperties,UV,PL spectra as well as DFT caculation were studied.The results showed that they diplayed rarely found column or three-dimensional cubic liquid crystalline phases,wherein the rod core branched compounds BPF12/10,BPF12/14,BPO12/12 displayed micellar cubic phases(CubI).Compared with fluorenone units,9-(biscyanomethylene)fluorene unit have better optical and conjugation properties,lower ELUMO and Eg.In addition,FA12/12.BP06/12?BP012/12?BPS6/12 compounds containing triazole heterocycles have selective response ability to recognize Cu2+,Fe3+,Hg2+ and other heavy metal ions;BPF12/14,BP06/12,BPO12/12 compounds in some organic solvents can form organic gels.The results of this study should be valuable for further study of these compounds.The third chapter is the experimental part,the synthesis of related compounds and the corresponding spectral data of each compound are introduced in detail.