Department of Physics, Graduate School of Science , Tohoku University , 6-3, Aramaki Aza-Aoba , Aoba-ku, Sendai , Miyagi 980-8578 , Japan.
School of Chemistry and Molecular Biosciences , The University of Queensland , St. Lucia , Queensland 4072 Australia.
Inorg Chem. 2018 Sep 17;57(18):11588-11596. doi: 10.1021/acs.inorgchem.8b01617. Epub 2018 Sep 6.
The ability to tune physical properties is attractive for the development of new materials for myriad applications. Understanding and controlling the structural dynamics in complicated network structures like coordination polymers (CPs) is particularly challenging. We report a series of two-dimensional CPs [Mn(salen)][M(CN)]· xHO (M = Pt (1), PtI (2), and MnN (3)) incorporating zigzag cyano-network layers that display composition-dependent anisotropic thermal expansion properties. Variable-temperature single-crystal X-ray structural analyses demonstrated that the thermal expansion behavior is caused by double structural distortions involving [Mn(salen)] units incorporated into the zigzag layers. Thermal relaxations produce structural transformations resulting in positive thermal expansion for 2·HO and negative thermal expansion for 3. In the case of 1·HO, the relaxation does not occur and zero thermal expansion results in the plane between 200 to 380 K. The present study proposes a new strategy based on structural distortions in coordination networks to control thermal responsivities of frameworks.
对开发用于各种应用的新材料而言，调节物理性能的能力极具吸引力。理解和控制配位聚合物（CPs）等复杂网络结构中的结构动力学尤其具有挑战性。我们报告了一系列二维 CPs [Mn(salen)][M(CN)]· xHO（M = Pt（1）、PtI（2）和 MnN（3）），其中包含锯齿形氰基网络层，表现出与组成相关的各向异性热膨胀性能。变温单晶 X 射线结构分析表明，热膨胀行为是由双结构变形引起的，其中 [Mn(salen)]单元被纳入锯齿层。热弛豫会产生结构转变，导致 2·HO 发生正热膨胀，3 发生负热膨胀。在 1·HO 的情况下，弛豫不会发生，在 200 至 380 K 之间的平面内会产生零热膨胀。本研究提出了一种基于配位网络结构变形的新策略，以控制框架的热响应性。
