硝基苯胺-冠醚包合物超分子晶体材料的合成、结构及介电性质

Synthesis,Structure and Dielectric Properties of Supramolecular Crystal Materials Containing Nitroaniline and Crown Ether

4-硝基苯胺和18-冠醚-6以物质的量比为1∶1在乙醇溶液内反应,通过室温蒸发合成硝基苯胺-冠醚包合物超分子晶体材料(4-NO2C6H4NH2)(18-冠醚-6)。并通过红外光谱(IR)、单晶X-射线衍射、X-射线粉末衍射(XRD)、热重(TG)、介电等测试方法对晶体的结构和性能进行表征和分析。结果显示目标化合物在室温和低温下属于单斜晶系,空间群为P21/n,晶体内4-硝基苯胺夹在两个平行的冠醚层间形成夹层结构,随着温度改变,冠醚层间距离发生伸缩,导致硝基与苯环平面及硝基苯胺分子与冠醚平面夹角发生改变,引起化合物介电常数随着温度的升高在260 K附近产生明显的增大。

4-Nitroaniline reacted with 18-crown-6 which was used as raw materials in ethanol solution at molar ratio of 1∶1.One nitroaniline-crown ether inclusion complex supramolecular crystalline material(4-NO2C6H4NH2)(18-crown-6)was successfully synthesized by evaporation method at room temperature.The structure and properties of the crystal were analyzed by IR,single crystal X-ray diffraction,X-ray powder diffraction(XRD),thermo gravimetry(TG)and dielectric measurements.The compound belongs to monoclinic system at room temperature(296 K)and low temperature(100 K)with the space group P21/n.4-Nitroaniline was sandwiched between the two parallel crown ether layers to form a sandwich structure in the crystal.The interlayer distances of crown ethers increase with the change of temperature,leading to the angle between nitro-benzene ring plane and nitroaniline molecule and crown ether plane is changed.This induced dielectric constant of the compound increased significantly around 260 K with the rise of temperature.