Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Dalton Trans. 2018 Jul 31;47(30):10071-10079. doi: 10.1039/c8dt02177e.
A new series of alkaline-earth-metal based coordination polymers were synthesized by using a pyrazine-2,5-dicarboxylic acid (2,5-H2pzdc) ligand under hydrothermal conditions. These compounds show a variety of structural topologies, reflecting the variable coordination geometries of the alkaline-earth ions as well as the key role of the metal precursor salts. Ca, Sr, and Ba give porous three-dimensional compounds, namely [Ca(2,5-pzdc)(H2O)2]·H2O (1), [Sr(2,5-pzdc)(H2O)4]·H2O (3), [Ba(2,5-pzdc)(H2O)4]·2H2O (4) and [Ba(2,5pzdc)(H2O)2] (5), that feature one-dimensional hydrophilic channels which are filled with water molecules. The Sr compound retains its structure when the lattice water molecules are removed, while the other compounds undergo a structural rearrangement. The hydrophilicity of the Sr compound combined with its high stability even in the absence of guest molecules are the key characteristics that determine its good water adsorption and proton conductivity properties.
在水热条件下，使用吡嗪-2,5-二羧酸（2,5-H2pzdc）配体合成了一系列新的碱土金属配位聚合物。这些化合物呈现出多种结构拓扑，反映了碱土金属离子可变的配位几何形状以及金属前体盐的关键作用。Ca、Sr 和 Ba 给出了多孔的三维化合物，分别为[Ca(2,5-pzdc)(H2O)2]·H2O（1）、[Sr(2,5-pzdc)(H2O)4]·H2O（3）、[Ba(2,5-pzdc)(H2O)4]·2H2O（4）和[Ba(2,5pzdc)(H2O)2]（5），它们具有一维亲水通道，通道中填充有水分子。Sr 化合物在去除晶格水分子时保留其结构，而其他化合物则经历结构重排。Sr 化合物的亲水性及其在没有客体分子存在时的高稳定性是决定其良好的水吸附和质子传导性能的关键特性。
