AbstractTwo compounds including a proton transfer ion pair, (pipzH2)(pdcH)2·2H2O (1) (where pipz: piperazine and pdcH2: pyrazole-3,5-dicarboxylic acid) and its Zn(II) complex (2), (pipzH2)[Zn(pdc)2(H2O)2]·6H2O, were synthesized and characterized using elemental analysis, IR spectroscopy and single crystal X-ray diffraction methods. The compound 1 crystallizes in the triclinic space group P$$\bar {1}$$1¯ with Z = 2. The unit cell dimensions are: a = 6.886(3) Å, b = 8.132(3) Å, c = 8.902(3) Å, α = 94.707(9)°, β = 99.632(9)°, γ = 111.508(8)°. The crystal system of 2 is monoclinic with space group P21/c and has two molecules per unit cell. The unit cell dimensions are: a = 12.050(2) Å, b = 13.163(2) Å, c = 7.610(1) Å, β = 97.610(4)°. The zinc(II) atom has a distorted octahedral coordination geometry. The two pdc2− units are almost coplanar to each other. In both crystal structures, a wide range of noncovalent interactions including hydrogen bonding (types of O–H⋯O, N–H⋯O and C–H⋯O), π–π stacking and ion pairing connect the various components into supramolecular structures.Graphical AbstractX-ray crystal structure of the novel 1:2 proton transfer compound, (pipzH2)(pdcH)2·2H2O (where pipz: piperazine and pdcH2: pyrazole-3,5-dicarboxylic acid) and its Zn(II) complex, (pipzH2)[Zn(pdc)2(H2O)2]·6H2O, show intermolecular N–H⋯O, O–H⋯O and C–H⋯O hydrogen bonds and π–π stacking, together with ion pairing, are responsible for extending the structure in three dimensions, resulting in a supramolecular network.

中文翻译：

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Piperazinium Bis(hydrogen-3,5-pyrazoledicarboxylate)质子转移化合物及其锌(II)配合物：合成、表征和晶体结构

摘要两种化合物包括质子转移离子对 (pipzH2)(pdcH)2·2H2O (1)（其中 pipz：哌嗪和 pdcH2：吡唑-3,5-二羧酸）及其 Zn(II) 配合物 (2)，（ pipzH2)[Zn(pdc)2(H2O)2]·6H2O，使用元素分析、红外光谱和单晶X 射线衍射方法合成和表征。化合物 1 在三斜空间群 P$$\bar {1}$$1¯ 中结晶，Z = 2。晶胞尺寸为：a = 6.886(3) Å, b = 8.132(3) Å, c = 8.902 (3) Å, α = 94.707(9)°, β = 99.632(9)°, γ = 111.508(8)°。2的晶系是单斜晶系，空间群为P21/c，每个晶胞有两个分子。晶胞尺寸为：a = 12.050(2) Å，b = 13.163(2) Å，c = 7.610(1) Å，β = 97.610(4)°。锌 (II) 原子具有扭曲的八面体配位几何结构。两个 pdc2− 单元几乎彼此共面。在这两种晶体结构中，广泛的非共价相互作用包括氢键（O-H⋯O、N-H⋯O 和 C-H⋯O 类型）、π-π 堆积和离子对将各种成分连接成超分子结构.图形摘要新型 1:2 质子转移化合物 (pipzH2)(pdcH)2·2H2O（其中 pipz：哌嗪和 pdcH2：吡唑-3,5-二羧酸）及其 Zn(II) 配合物的 X 射线晶体结构, (pipzH2)[Zn(pdc)2(H2O)2]·6H2O，显示分子间 N-H⋯O、O-H⋯O 和 C-H⋯O 氢键和 π-π 堆积，以及离子对，负责在三个维度上扩展结构，从而形成超分子网络。