二维氢键型[(C_(5)N_(5)H_(7))·(I_(3)·H_(2)O)_(2)]材料的合成及介电性能研究

Synthesis and Dielectric Properties Study of Two-dimensional Hydrogen-bonding Material[(C_(5)N_(5)H_(7))·(I_(3)·H_(2)O)_(2)]

室温下以腺嘌呤、碘化镉和氢碘酸为原料,以水为溶剂,通过室温蒸发法获得一种氢键型二维网状结构的有机-无机杂化材料[(C_(5)N_(5)H_(7))·(I_(3)·H_(2)O)_(2)](1),通过单晶X-射线衍射、红外光谱(IR)、粉末X射线衍射(XRD)、热重分析(TG)、变温-变频介电常数测试对晶体的结构、热性能和电性能进行分析。单晶结构解析显示化合物属于单斜晶系,空间群为P 2_(1)/n。在ab平面上腺嘌呤阳离子、碘阴离子和水分子通过N-H…O、N-H…N、C-H…I和C-H…O氢键作用形成形成二维网状结构。通过变温变频介电测试中发现升温过程中,晶体在240~270 K温度范围内产生显著的介电异常现象,但在1 MHz频率下升温和降温过程产生循环介电曲线,显示材料在双稳态及介电开关等领域有潜在应用。

An organic-inorganic hybrid material[(C_(5)N_(5)H_(7))·(I_(3)·H_(2)O)_(2)](1)with a hydrogen-bonded two-dimensional network structure was obtained by room temperature evaporation using adenine,cadmium iodide,and hydriodic acid as raw materials,and water as solvent.The crystal was analyzed for its structural,thermal,and electrical properties by single-crystal X-ray diffraction,infrared(IR)spectroscopy,powder X-ray diffraction(XRD),thermogravimetric analysis(TG),and variable-temperature dielectric constant test.Structural analysis of the single crystals reveals the compounds belong to the monoclinic crystal system with the space group P 2_(1)/n.A two-dimensional network structure was formed by adenine cations,iodine anions and water molecules through N-H…O,N-H…N C-H…I and C-H…O hydrogen-bonding interactions in the ab-plane.The crystals were found to produce significant dielectric anomalies in the temperature range of 240 to 270 K and cyclic dielectric curves at a frequency of 1 MHz through variable temperature and frequency dielectric tests,suggesting potential applications in bistability and dielectric switching fields.