Anomalous Dielectric Behaviour and Thermal Motion of Water Molecules Incorporated in Porous Crystals
Anomalous Dielectric Behaviour and Thermal Motion of Water Molecules Incorporated in Porous Crystals
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多孔晶体中水分子的反常介电行为和热运动
DOI：
10.1002/pssc.201100717
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and Hayao Kobayashi
中科院分区：
文献类型：
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作者：
Biao Zhou;Akiko Kobayashi;Zhe-Ming Wang;La-Sheng Long;and Hayao Kobayashi
通过物理测量和分子动力学模拟相结合的方法，我们研究了多孔配位聚合物晶体通道中客体水分子的介电性质。[Ln_2Cu_3（IDA）_6] ·nH_2O（Ln = La，Nd，Sm，Gd，Ho，Er; IDA = [NH（CH_2COO）_2]_2-;n = 9）在高温下表现出较大的介电常数和反铁电行为。特别是[Sm 2Cu 3（IDA）6] ·nH 2 O的ε在400 K附近达到1300。此外，晶体在约170 K处表现出宽的介电峰，低于该介电峰时ε变得非常小，这表明客体水分子的位置自由度被冻结。[Cu（IN）2] ·nH 2 O（IN =（C6 H4 NO2）-）的介电常数随温度的升高而迅速增加，这归因于氢键水链系统的熔化。这些ε的温度依赖性与MD模拟结果一致（© 2012 WILEY-VCH Verlag GmbH & Co. KGaA，魏因海姆）
By combining physical measurements and molecular dynamics (MD) simulations, we investigated the dielectric properties of guest water molecules confined in the channels of porous coordination polymer crystals. [Ln2Cu3(IDA)6] ·nH2O (Ln = La, Nd, Sm, Gd, Ho, Er; IDA = [NH(CH2COO)2]2‐;n≈ 9) exhibited large dielectric constants (ε) and antiferroelectric behaviours at high temperatures. In particular,εof [Sm2Cu3(IDA)6] ·nH2O became as large as 1300 at around 400 K. In addition, the crystals exhibited broad dielectric peaks at around 170 K below whichεbecame very small, indicating the freezing of the positional freedom of guest water molecules. The dielectric constants of [Cu(IN)2] ·nH2O (IN = (C6H4NO2)‐) also increased fairly rapidly with temperature, which attributed to the melting of the hydrogen‐bonded water chain system. These temperature dependences ofεwere consistent with the results of MD simulation (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)