| 1，4-二氮杂二环[2.2.2]辛烷-氰基合钴(Ⅲ)三维框架氢键型晶体的合成、相变及介电性质 |
| Synthesis, Phase Transition and Dielectric Properties of 1,4-Diazabicyclo[2.2.2]octane-Cyanide Cobalt(Ⅲ) Three-Dimensional Framework Hydrogen-Bonding Crystal |
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| 摘要: 室温下以1，4-二氮杂二环[2.2.2]辛烷（Dabco）和钴氰酸为原料、水和甲醇为混合溶剂，以缓慢蒸发的方式获得Dabco-氰基合钴氢键型框架晶体材料（H3O）（H2Dabco）[Co （CN）6]·H2O （1）。并通过单晶X射线衍射、红外光谱、元素分析、粉末X射线衍射、热重分析、差示扫描量热、变温-变频介电常数测试对其结构、热性能与电性能进行表征。在低温（100 K）与室温（296 K）下，化合物均为单斜晶系P21/c空间群。单晶结构显示氰基合钴阴离子、水分子与水合质子在晶体内部通过氢键的相互作用形成三维网状框架，质子化的（H2Dabco）2+阳离子镶嵌在其中构成分子马达型囊状结构。随着温度的升高（H2Dabco）2+阳离子发生弹簧式扭转，从而引发晶体在254 K附近相变，在相同温度下沿着晶体的3个轴向发生介电异常，呈现明显的介电各向异性。 |
| 关键词: 晶体结构 氢键 三维框架结构 相变 介电性质 |
| 基金项目: 国家自然科学基金（No.21561030）和新疆维吾尔自治区研究生科研创新项目（No.XJ2021G131）资助。 |
| Abstract: A Dabco-cobalt cyanide hydrogen-bonding framework crystal material, (H3O)(H2Dabco)[Co(CN)6]·H2O (1), has been synthesized by solvent evaporation in the mixed solution of methanol and water with 1,4-diazabicyclo[2.2.2]octane (Dabco) and cobalt cyanide. The structure, thermal energy and electrical properties of the crystal were characterized by single crystal X-ray diffraction, infrared spectroscopy, elemental analysis, X-ray powder diffraction, thermogravimetric analysis, differential scanning calorimetry and variable temperature-frequency dielectric constant test. The space group of the crystal is P21/c, which belongs to the monoclinic system at low and room temperature. The structure shows that the cobalt cyano anion, water molecules and protonated water molecules are mutually connected through hydrogen bonds in the crystal to form a three-dimensional network framework, and the protonated (H2Dabco)2+ cations are embedded in it forming a molecular motor-type cystic structure. With the increase of temperature, the (H2Dabco)2+ cations are twisted, which causes a phase transition in the crystal structure near 254 K. Dielectric anomalies occurs along the three axes of the crystal, showing obvious dielectric anisotropy at the same temperature. |
| Keywords: crystal structure hydrogen bond three-dimensional framework structure phase transition dielectric properties |
| 投稿时间：2021-02-21 修订日期：2021-08-29 |
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| 徐慧婷,刘洋,秦刘磊,齐欢欢,刘尊奇.1，4-二氮杂二环[2.2.2]辛烷-氰基合钴(Ⅲ)三维框架氢键型晶体的合成、相变及介电性质[J].无机化学学报,2021,37(11):1950-1960. |
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