摘要
以1.4-二氮杂二环[2.2.2]辛烷(DABCO)氟硼酸盐与(NH_(4))_(3)[FeMo_(6)O_(24)H_(6)]·7H_(2)O多酸盐为原料,通过H管水溶液界面扩散方式合成一种新颖的Anderson型超分子化合物(H_(2)DABCO)_(2)[FeMo_(6)O_(24)H_(4)]·4H_(2)O(1)。并通过红外光谱、单晶X衍射、元素分析、XRD粉末衍射、热重分析(TG)、差示扫描量热法(DSC)和介电常数测试等方式对化合物的结构、热稳定性及电学性质进行表征。单晶X衍射结果显示该晶体在低温-室温下都属于三斜晶系,空间群为P-1,其多酸阴离子与水分子之间通过氢键作用形成二维网状结构,水分子随着温度的变化产生了明显的移动,而DABCO阳离子通过N-H…O氢键填充在相邻多酸阴离子的二维层状结构内,随温度的变化发生明显的分子扭动,导致化合物1在233K和271K附近产生相转移峰和阶梯型介电常数可逆现象。
A new Anderson supramolecular compound(H_(2)DABCO)_(2)[FeMo_(6)O_(24)H_(4)]·4H_(2)O(1)was synthesized by 1.4-diazodicylic[2.2.2]octane(DABCO),(NH_(4))_(3)[FeMo_(6)O_(24)H_(6)]·7H_(2)O and tetrafluoroboric acid using water as solvent through H-tube interface diffusion method.The structure,thermal stability and electrical properties of supramolecular compounds were characterized by infrared spectroscopy,single crystal X-ray diffraction,elemental analysis,XRD,TG,DSC and dielectric constant testing.The results of single crystal X-ray diffraction prove that the crystal at low temperature belongs the triclinic space group P-1.The polyacid anions and water molecules form a two-dimensional network structure through hydrogen bondings,water molecules move appreciably with the change of temperature.DABCO cation is filled in the two-dimensional layered structure of adjacent poly acid anions with N-H…O hydrogen bondings and significant molecular writhing occurs with temperature.This results in the phase transition and reversible phenomenon of stepped dielectric constant around 233 K and 271 K.
作者
胡宏志
刘洋
袁玉杰
杨芳
秦刘磊
刘尊奇
HU Hong-zhi;LIU Yang;YUAN Yu-Jie;YANG Fang;QIN Liu-lei;LIU Zun-qi(Chemical Engineering College,Xinjiang Agricultural University,Urumqi 830052,China)
出处
《化学研究与应用》
CAS
CSCD
北大核心
2022年第1期7-17,共11页
Chemical Research and Application
基金
国家自然基金项目(21561030)资助
新疆维吾尔自治区研究生科研创新项目(XJ2021G131)资助
新疆农业大学大学生创新项目(2021104)资助。
关键词
晶体结构
氢键
多酸盐
相变
介电性质
crystal structure
hydrogen bonding
heteropoly acid salt
phase transition
dielectric properties
