Hydrogen-Bonding Assembly of Coordination Polymers Showing Reversible Dynamic Solid-State Structural Transformations
Hydrogen-Bonding Assembly of Coordination Polymers Showing Reversible Dynamic Solid-State Structural Transformations
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DOI：
10.3390/inorganics6040115
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发表时间：
2018-10
期刊：
影响因子：
2.9
通讯作者：
H. Kumagai;Sadahiro Yagishita;Ken Kanazashi;M. Ishii;S. Hayami;H. Konaka;Ryuta Ishikawa;S. Kawata
中科院分区：
文献类型：
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作者：
H. Kumagai;Sadahiro Yagishita;Ken Kanazashi;M. Ishii;S. Hayami;H. Konaka;Ryuta Ishikawa;S. Kawata
我们在此报告了配位聚合物的合成、单晶结构以及使用1,4,5,6-四氢-5,6-二氧代-2,3-吡嗪二甲腈（tdpd2-）和吡嗪（pyz）作为桥联配体的配合物的结构转变。 {[M(H2O)4(pyz)][M(tdpd)2(pyz)]·6(H2O)}n，[1·10H2O 和 2·10H2O，其中 M = Co (1) 和 Zn (2)]，由两种晶体学上独立的一维 (1D) 结构堆积在一起组成。一个基序 [M(tdpd)2(pyz)]2− (A) 是带有螯合 tdpd2− 配体的阴离子无限 pyz 桥接一维阵列，另一个基序是阳离子链 [M(H2O)4(pyz)]2+ (B)，其装饰有四个末端水分子。一维阵列 (A) 和 (B) 通过多点氢键相互作用以沿 c 轴延伸的交替 (A)(B)(A)(B) 序列平行排列。两种化合物在 350 K 左右的热脱水过程驱动下表现出结构转变，得到部分脱水形式 1·2H2O 和 2·2H2O。部分脱水形式 2·2H2O 的结构测定揭示了从一维链结构到二维 (2D) 配位片结构 [Zn2(tdpd)2(H2O)2(pyz)]n (2·2H2O) 的固态结构转变。进一步加热至 500 K 产生无水形式 2。虽然 1·10H2O 和 2·10H2O 的原始样品在不同的晶系中结晶，但脱水形式 1·2H2O 和 2·2H2O 的粉末 X 射线衍射 (PXRD) 测量表明具有相同的结构。在环境条件下，1·10H2O 的结构转变是不可逆的。另一方面，化合物2·10H2O表现出可逆的结构变化。通过监测原位磁化率也证实了 1·10H2O 的固态结构转变，这与其他热感应测量一致。
We herein report the synthesis, single-crystal structures of coordination polymers, and structural transformations of complexes employing 1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile (tdpd2−) and pyrazine (pyz) as bridging ligands. {[M(H2O)4(pyz)][M(tdpd)2(pyz)]·6(H2O)}n, [1·10H2O and 2·10H2O where M = Co (1) and Zn (2)], consists of two types of crystallographically independent one-dimensional (1D) structures packed together. One motif, [M(tdpd)2(pyz)]2− (A), is an anionic infinite pyz bridged 1D array with chelating tdpd2− ligands, and the other motif is a cationic chain, [M(H2O)4(pyz)]2+ (B), which is decorated with four terminal water molecules. The 1D arrays (A) and (B) are arranged in parallel by multi-point hydrogen-bonding interactions in an alternate (A)(B)(A)(B) sequence extending along the c-axis. Both compounds exhibit structural transformations driven by thermal dehydration processes around 350 K to give partially dehydrated forms, 1·2H2O and 2·2H2O. The structural determination of the partially dehydrated form, 2·2H2O, reveals a solid-state structural transformation from a 1D chain structure to a two-dimensional (2D) coordination sheet structure, [Zn2(tdpd)2(H2O)2(pyz)]n (2·2H2O). Further heating to 500 K yields the anhydrous form 2. While the virgin samples of 1·10H2O and 2·10H2O crystallize in different crystal systems, powder X-ray diffraction (PXRD) measurements of the dehydrated forms, 1·2H2O and 2·2H2O, are indicative of the same structure. The structural transformation is irreversible for 1·10H2O at ambient conditions. On the other hand, compound 2·10H2O shows a reversible structural change. The solid-state structural transformation for 1·10H2O was also confirmed by monitoring in-situ magnetic susceptibility, which is consistent with other thermally-induced measurements.