| The ferroelectric phase change materials have showed great potential applications in the field of switchable dielectric materials,data storage,sensing,signal processing etc.In addition,the complexes with multi-function or specific structure are of immense implementation prospect in adsorption,catalysis,luminescence,magnetism.In this paper,six ferrocene carboxylic acid compounds,two amide compounds and one tetrazole complexe were successfully synthesized.X-ray single crystal diffraction,dielectric measurement,differential scanning calorimetry?DSC?,fluorescence measurement were performed to research their structures,optical property and ferroelectric properties.The main contents are as follows:In chapter 1,By use of driving/controlling force from rotating motion of cyclopentadienyl rings for a reversible structural transition,then making structural modifications on the local parts of them to create remnant polarization through this molecule system,we designed and constructed a new ferroelectric,the adduct of hexamethylenetetramine ferrocene carboxylic acid,(C6H12N4)[Fe?C5H5??C6H5O2?]?1?and(C6H14N4)[Fe?C5H5??C6H4O2?]2?2?.Compound 1undergoes a reversible structural phase transition around 187 K and a dipole moment from amine group to carboxylic acid in the low temperature produces the net spontaneous polarization,then results the ferroelectricity in 1-LTP.The further investigation shows it has a better ferroelectric hysteresis loop with spontaneous polarizations 3.95 uC/cm2.Compound 2possesses reversible phase change properties,of which the high and low temperature structures belong to the polar space group Fmm2,but its ferroelectricity needs to be further determined.Next,compounds 3 and 4 were synthesized by reacting ferrocene carboxylic acid 1,3-propanediamine and piperazine.In addition,ferrocene carboxylic acid metal complexes 5 and6 have been successfully synthesized,which include ferrocene carboxylic acid ions with different kinds of cyclopentadiene ring structures.In chapter 2,we reported two new crown ether clathrates,[Habf-?18-crown-6?1.5]+[PF6]-?7?and[Habf-?18-crown-6?]+[ClO4]-?8??Habf=p-ammonium benzene formamide?,7 shows an interesting reversible phase transition near room temperature?263 K?.X-ray single crystal diffractions analysis shows that the synergetic rotation motion between the 18-crown-6 crown ethers and the order-disorder motions of both hexafluorophosphate guest anions and 18-crown-6 crown ethers host molecules lead to the phase transition.This reversible phase transition behavior was confirmed by its evident thermal anomaly behavior at around 263 K.The apparent step-like dielectric change around the phase transition indicates that it has potential application in the dielectric switches.In addition,by using phosphoric acid instead of hexafluorophosphoric acid as the inorganic acid in the reaction,and no crown ether was added,the compound(C7H12N2O)2?HPO4?2?9?was synthesized by the same method,and this compound also exhibited low-temperature reversible phase change properties.In this paper,we compare the structural kinetics,thermal properties and dielectric anomalies of compounds 7,8 and 9 in detail.In chapter 3,Hydrothermal reaction of CuSO4·7H2O,NaN3 with 2-cyanothiophene in aqueous ethanol yielded a novel tetranuclear copper?I?polymer,{[Cu4?tptz?4]·0.5?C2H6O?}n,?10??Htptz=5-?thiophen-2-yl?-1H-tetrazole?.Infrequently,three total different geometries of Cu?I?cations namely the linear,triangle and tetrahedron geometries of Cu?I?centers are discovered and linked by Htptz ligands into a one dimensional ladder structure.Additionally,10 exhibits strong blue fluorescence?with?=467 nm?at room temperature in the solid state. |
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