Composition Space Analysis in the Development of Copper Molybdate Hybrids Decorated by a Bifunctional Pyrazolyl/1,2,4-Triazole Ligand

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• 作者：Andrey B. Lysenko ; Ganna A. Senchyk ; Liliana V. Lukashuk ; Konstantin V. Domasevitch ; Marcel Handke ; J?rg Lincke ; Harald Krautscheid ; Eduard B. Rusanov ; Karl W. Kr?mer ; Silvio Decurtins ; Shi-Xia Liu
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：January 4, 2016
• 年：2016
• 卷：55
• 期：1
• 页码：239-250
• 全文大小：962K
• ISSN：1520-510X

文摘

A bitopic ligand, 4-(3,5-dimethylpyrazol-4-yl)-1,2,4-triazole (Hpz-tr) (<b>1b>), containing two different heterocyclic moieties was employed for the design of copper(II)–molybdate solids under hydrothermal conditions. In the multicomponent Cu^II/Hpz-tr/Mo^VI system, a diverse set of coordination hybrids, [Cu(Hpz-tr)b>2b>SOb>4b>]·3Hb>2b>O (<b>2b>), [Cu(Hpz-tr)Mob>3b>Ob>10b>] (<b>3b>), [Cub>4b>(OH)b>4b>(Hpz-tr)b>4b>Mob>8b>Ob>26b>]·6Hb>2b>O (<b>4b>), [Cu(Hpz-tr)b>2b>Mob>4b>Ob>13b>] (<b>5b>), and [Mob>2b>Ob>6b>(Hpz-tr)]·Hb>2b>O (<b>6b>), was prepared and characterized. A systematic investigation of these systems in the form of a ternary crystallization diagram approach was utilized to show the influence of the molar ratios of starting reagents, the metal (Cu^II and Mo^VI) sources, the temperature, etc., on the reaction products outcome. Complexes <b>2b>–<b>4b> dominate throughout a wide crystallization range of the composition triangle, while the other two compounds <b>5b> and <b>6b> crystallize as minor phases in a narrow concentration range. In the crystal structures of <b>2b>–<b>6b>, the organic ligand behaves as a short [N–N]-triazole linker between metal centers Cu···Cu in <b>2b>–<b>4b>, Cu···Mo in <b>5b>, and Mo···Mo in <b>6b>, while the pyrazolyl function remains uncoordinated. This is the reason for the exceptional formation of low-dimensional coordination motifs: 1D for <b>2b>, <b>4b>, and <b>6b> and 2D for <b>3b> and <b>5b>. In all cases, the pyrazolyl group is involved in H bonding (H-donor/H-acceptor) and is responsible for π–π stacking, thus connecting the chain and layer structures in more complicated H-bonding architectures. These compounds possess moderate thermal stability up to 250–300 °C. The magnetic measurements were performed for <b>2b>–<b>4b>, revealing in all three cases antiferromagnetic exchange interactions between neighboring Cu^II centers and long-range order with a net moment below Tb>cb> of 13 K for compound <b>4b>.