| Metal-organic framework as an important material building block is easy to produce a variety of physical properties,especially the metal-cyano complex,which can be deformation,becoming a chain,a net etc.,has become a research hotspot on small molecular metal-organic functional materials.Crown ether macrocyclic compounds and amino organic small molecules can be assembled into supramolecular structures and form a crystal functional material with a one-dimensional and multidimensional structure of cyano-group metal frame.Crystal compounds contain a large number of hydrogen bonds,and it is easy to produce molecular rotation,swing and proton transfer through changes in external conditions,resulting in dielectric abnormalities and phase transfer.This kind of material has rich and changeable structure,excellent physical and chemical properties,and has good application prospects in the fields of catalysis,energy storage,electrical,magnetic,optical,pharmaceutical and other fields.In this thesis,we have synthesized seven supermolecular functional material compounds of cyano-group metallic complexes which have not been reported in the literature,and infrared spectrum,single Crystal X-ray diffraction and thermogravimetric analysis were used to determine the composition and structural analysis of the above compounds,and their electrical properties were studied by differential scanning calorimetry,dielectric constant measurements,and ferroelectric tests.By solvent evaporation methods,using 2-chloroaniline,2-bromoaniline,3-aminobenzamide,18-crown6 and hexacyano-cobaltanoic acid as raw materials to obtain a cyano-cobalt crown ether supramolecular compound 1-3:(C6H7NCl)0.5(18-crown-6)0.5[Co(CN)6]0.5H2.5O(1);(C6H7NBr)(18-crown6)0.5[HCo(CN)6]0.5(H2O)(2);(C7H9N2O)(18-crown-6)[H2Co(CN)6](H2O)5(3).Imidazole,3aminobenzamide,8-crown-6,and hexacyanoferric acid were used as raw materials to obtain a cyano-iron crown ether supramolecular compound 4-5:(C3H5N2)3(18-crown-6)2[Fe(CN)6](H2O)2(4);(C7H9N20)(1 8crown-6)[HFe(CN)6]1/2(CH3OH)(5).Using ferric chloride,cobalt chloride,potassium thiocyanate,and 18crown-6 as raw materials,a thiocyanometallic crown ether supramolecular compound 6-7 was obtained:[K(18-crown-6)][Fe(NCS)5]1/2(6);[K(18-crown-6)]2[Co(NCS)4](H2O)2(7).Compound 1-3 is a multi-dimensional compound based on[Co(CN)6]n-as the building unit.The dynamic oscillation of supramolecular motor with temperature and the expansion and contraction deformation of[Co(CN)6]n-frame lead to compound 1-3 respectively Dielectric anomalies occurring at 280 K,270 K,and 220 K are all dielectric abnormal crystal materials.Compound 3 shows good ferroelectricity and belongs to ferroelectric-dielectric materials.Compound 4-5 is a supramolecular compound based on[Fe(CN)6]n-unit.With the change of external temperature,the dynamic swing of supramolecular cation structure and deformation of[Fe(CN)6]n-frame make compound 4-5 respectively.It causes reversible phase transitions around 265 K and 210 K,and dielectric anomalies in the range of 200 K-270 K.It belongs to phase-dielectric anomaly type materials.Compounds 6-7 are based on[Fe(NCS)5]2-,[Co(NCS)4]2-units to construct modules,the change of the car-like structure in compound 6-7 with temperature leads to a phase change of the crystal at about 250 K and 230 K,and dielectric anomalies occur in the range of 220 K-280 K and 230 K-270 K.The difference makes compound 6 highly polarized and exhibits strong ferroelectricity.At 233 K,the saturation spontaneous polarization reaches 2.130 ?C/cm2. |
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