Synthesis Of Ionic Supramolecular Liquid Crystals Containing Cholesteryl Group

Ionic liquid crystals(ILCs)and ionic liquid-crystalline polymers(ILCPs)are the kinds of supramolecular materials that contain ions and show liquid crystalline behaviors.They are functional compounds that have developed on the basis of liquid crystals and ionic compounds.They show not only unique optical and electromagnetic properties of liquid crystals,but also good electromagnetic performance,mechanical properties,and good chemical stability of ionic compounds.As a kind of novel functional materials,ILCs and ILCPs are not only applied in many interdisciplinary fields such as physics,chemistry,materials science and so on,but also have potential application prospect in the fields such as information,military science,printed circuit,optics and composite materials.Based on new attempt to synthesize this kind of functional materials,novel ILCs and ILCPs of self-assembling supramolecular materials containting N element and cholesteryl group were designed and synthesized in this dissertation.Firstly,three monomers were synthesized,which were cholesteryl 4-bromobutyrate(M₁),phloroglucinol isonicotinate(M₂)and pentaerythritol isonicotinate(M₃).Then bromide-type ILCs([Ia-K]Br)and ILCPs(P series)were synthesized using M₁ and M₂,M₃,4,4'-bipyridine,hexamethylenetetramine,(29H,3¹H-phthalocyaninato(2-)-N₂₉,N₃₀,N₃₁,N₃₂)copper,polyethylenimine(PET),respectively.Series of supramolecular ILCs([Ia-BTl][X],[Ia-blPD][X],[Ia-bPy][X],[Ia-HMA][X],[Ia-Phth][X])and ILCPs([P₁][CF₃COO^-],[P₂][BF₄^-]and[P₃][PF₆^-])were synthesized by a replacement reaction using each compounds of[Ia-K]Br and P series with fluoroboric acid,hexafluorophosphoric acid,trifluoroacetic acid,p-toluene-sulfonic acid and D-Camphorsulfonic acid,respectively.The chemical structures,thermal properties and liquid crystalline properties of these synthesized monomers,ILCs and ILCPs were characterized by use of Fourier transform infrared spectroscopy(FT-IR),hydrogen-nuclear magnetic resonance(¹H-NMR),differential scanning calorimetr(DSC),polarizing optical microscope(POM),X-ray diffraction(XRD),and so on.The results showed that chemical structures of the monomers,ILCs and ILCPs were accordance with the molecular design.The monomer M₁,ILCs and ILCPs have liquid-crystal characters and show cholesteric or smectic mesophase.For the bromide-type ILCs,the melting point(Tm)decreased with increasing of mesogenic units in space structures which should be due to increase of M₁ component and pyridyl ring moieties.For the bromide-type P series of ILCPs,Tm and the cleaning point temperature(Ti)decreased with increase of M₁ component.For the same series of ILCs and ILCPs bearing different anions,the ILCs and ILCPs containing other anions except for Br^-showed a wider mesomorphic range than the corresponding mother bromide-type ILCs and ILCPs.Furthermore,Tm decreased in different degrees,and Ti decreased in the order of PF₆^-,BF₄^-,CF₃COO^-,Ts^-and Br^-.Moreover,the glass transition temperature(Tg)showed little changes for the ILCPs with different anions.The research in this dissertation is full of theoretic and practical meaning,and it provides material for theory and some necessary laboratory technical support for further application of ionic liquid-crystals supramolecular and ILCPs.