Hydrothermal Synthesis and Structure of Coordination Polymers by Combination of Bipyrazole and Aromatic Dicarboxylate Ligands

Nine new coordination polymers, namely 2∞[Ag(Hp2CA)(Me4bpz)] (I), 3∞[Zn2(p2CA)2(Me4bpz)] (II), 2∞[Cd(OAc)2(Me4bpz)(H2O)] (III), 1∞[Ag2(m2CA)(Me4bpz)2] (IV), 3∞[Zn(m2CA)(Me4bpz)] (V), 2∞[Cd(m2CA)(Me4bpz)]·H2O (VI), 1∞[Ag(OAc)(Me4bpz)2]·5.4 H2O (VII), 3∞[Zn2(OHm2CA)2(Me4bpz)2]·1.75 H2O (VIII), and 2∞[Cd(OHm2CA)(Me4bpz)(H2O)] (IX) [Hp2CA, terephthalic acid monoanion; p2CA, terephthalic acid dianion; OAc, acetate; m2CA, isophthalic acid dianion; OHm2CA, 5-hydroxy-isophthalic acid dianion; Me4bpz, 3,3′,5,5′-tetramethyl-4,4′-bipyrazole], were obtained from acetate hydrates of Ag+, Zn2+, and Cd2+ and mixed ligand systems consisting of Me4bpz and the respective aromatic dicarboxylic acid by means of hydrothermal synthesis. The compounds were characterized by means of X-ray single-crystal structure analysis, elemental analysis, and IR spectroscopy. The topologies realized in these coordination polymers vary from simple one-dimensional polymers to complex three-dimensional frameworks. Hydrogen bonds of different types with influence on the resulting structures are observed in all compounds.

本研究通过水热合成法，以Ag+、Zn2+与Cd2+的乙酸盐水合物为金属前驱体，结合由3,3',5,5'-四甲基-4,4'-联吡唑（Me4bpz）与对应芳香二羧酸构成的混合配体体系，成功合成了9种新型配位聚合物，具体包括：2∞[Ag(Hp2CA)(Me4bpz)]（I）、3∞[Zn2(p2CA)2(Me4bpz)]（II）、2∞[Cd(OAc)2(Me4bpz)(H2O)]（III）、1∞[Ag2(m2CA)(Me4bpz)2]（IV）、3∞[Zn(m2CA)(Me4bpz)]（V）、2∞[Cd(m2CA)(Me4bpz)]·H2O（VI）、1∞[Ag(OAc)(Me4bpz)2]·5.4H2O（VII）、3∞[Zn2(OHm2CA)2(Me4bpz)2]·1.75H2O（VIII）以及2∞[Cd(OHm2CA)(Me4bpz)(H2O)]（IX）。其中，Hp2CA为对苯二甲酸单阴离子（terephthalic acid monoanion），p2CA为对苯二甲酸二阴离子（terephthalic acid dianion），OAc为乙酸根（acetate），m2CA为间苯二甲酸二阴离子（isophthalic acid dianion），OHm2CA为5-羟基间苯二甲酸二阴离子（5-hydroxy-isophthalic acid dianion），Me4bpz为3,3',5,5'-四甲基-4,4'-联吡唑（3,3′,5,5′-tetramethyl-4,4′-bipyrazole）。所有化合物均通过X射线单晶结构分析、元素分析与红外光谱完成了表征。该系列配位聚合物的拓扑结构丰富多样，涵盖从简单一维聚合物到复杂三维骨架的多种类型。所有化合物中均存在不同类型的氢键，且此类氢键对最终晶体结构的形成具有显著影响。