Studies On Transition Properties Of Quaternary Ammonium Salts And Cyclic Amine Crystals

The prosperity of the information age has brought unprecedented opportunities for the development of phase transition materials,at the same time,the threshold for the application of materials is also rising.Traditional phase transition materials are already incapable of meeting the needs of society.More and more gumption of research is projected on multifunctional molecule-based phase transition materials.It is true that this step is of far-reaching significance to the study of phase transition materials,which makes the traditional phase transition materials of single nature achieve a gorgeous change,effectively combing the switchable phase transition properties with other excellent properties such as light and electricity,and greatly expanding the application areas of phase transition materials.However,it must be admitted that there are still very few multifunctional phase transition materials with excellent performance at present,and research on the design and performance optimization of the crystal structure of the material still needs to be in-depth.Organic-inorganic hybrid materials have the dual advantages of organic and inorganic components,and the structure is rich and easy to control,making it possible to study the crystal structure design of phase transition materials.As an important carrier of the switchable function of the material,the dielectric property is a sensitive signal for detecting the structural phase transition,thus its significance in the material performance evaluation is self-evident.Therefore,we designed and synthesized a series of organic-inorganic hybrid materials using quaternary ammonium salts,heterocyclic amine salt,and benzene ring-containing salts as organic ligands,and explored the internal crystal structure and dielectric properties of the materials.In this article,we divided these materials into three major modules and introduce them separately.The first module is comprised of compounds respectively synthesized with isopropyltrimethylammonium bromide,hydroxyethyltrimethylammonium bromide,and cyclopentyltrimethylammonium bromide,including[C₁₂H₃₂N₂][CdBr₄](Compound 1),[C₁₂H₃₂N₂][Mn Br₄](Compound 2),[C₈H₂₀NO][CdBr₄](Compound 3),[C₁₆H₃₂N₂][Zn Br₄](Compound 4).The second module is comprised of compounds synthesized with mepiquat chloride as organic cation and inorganic salt SbCl₂,Ni Cl₂,CdBr₂ as anionic metal skeleton,including[C₁₄H₃₂N₂][SbCl₄](Compound 5),[C₁₄H₃₂N₂][Ni(SCN)₆](Compound 6),[C₁₄H₃₂N₂][CdBr₄](Compound 7)these three organic-inorganic hybrid materials.The third module is comprised of compounds respectively synthesized with meta-chloroaniline,3-fluoro,4-chloroaniline,and N-methylbenzylamine as organic ligands,including[C₆H₇NCl][CCl₃COO](Compound 8),[C₆H₆NCl F][CCl₃COO](compound 9),[C₈H₁₁N]₄[Bi₂Cl₁₀](compound 10)these three organic-inorganic hybrid materials.Using differential scanning calorimetry,variable temperature single crystal X-ray diffraction,dielectric measurement and other characterization methods to explore the crystal structure and physical and chemical properties of the material,we found that among these 10 compounds,compounds 1,2,4,5,6,7 having phase transition behaviors,and there are obvious structural phase transition characteristics.In the meanwhile,compound 2 also has excellent fluorescence properties,which contributes some ideas to the research of multifunctional switchable phase transition materials.