One-Pot, Template Syntheses of a New Class of Metallomacrocycles with a Tetraoxime Cyclic Skeleton
One-Pot, Template Syntheses of a New Class of Metallomacrocycles with a Tetraoxime Cyclic Skeleton
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DOI：
10.1021/ic900993j
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发表时间：
2009-11-02
影响因子：
4.6
通讯作者：
Shionoya, Mitsuhiko
中科院分区：
文献类型：
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作者：
Tashiro, Shohei;Minoda, Ai;Shionoya, Mitsuhiko
最常见的大环化合物，如冠醚、卟啉和大环多胺，在配位化学、超分子化学、分析化学和材料科学等多种研究领域显示出多功能、优异的功能。因此，合理设计一类易于合成的新型大环金属配体是开发一类新型功能化大环金属配合物的关键。在此，我们报告了在模板过渡金属离子（例如 Fe2+、Ni2+、Cu2+、Co2+ 或 Ag+）存在下，从二肟一锅模板合成具有 16 元四肟环状骨架的新型金属大环化合物。这些金属离子可以很容易地从单核金属大环中去除，例如，当使用 Fe2+ 作为模板时，可以以 90% 的收率获得不含金属的四肟配体。看来这种一锅式金属模板 Pd2+ 环化通过连续的金属介导的肟交换反应有效地进行。有趣的是，它不提供任何环化产物，与大环配体形成1:1复合物。单晶X射线分析完全确定了无金属配体的分子结构，其与Fe2+、Ni2+、Cu2+、Pd2+和Ag+的1:1金属配合物以及与Ag+的双核配合物。还报道了这些配合物的紫外-可见吸收光谱和循环伏安法测量。
Most common macrocycles such as crown ethers, porphyrins, and macrocyclic polyamines show versatile, excellent functions in a variety of research fields such as coordination chemistry, supramolecular chemistry, analytical chemistry, and material sciences. Thus, the rational design of a new class of readily synthesized macrocyclic metal ligands is a key to the development of a new category of functionalized macrocyclic metal complexes. Herein, we report one-pot, template syntheses of a new class of metallomacrocycles with a 16-membered tetraoxime cyclic skeleton from a dioxime in the presence of a template transition-metal ion such as Fe2+, Ni2+, Cu2+, Co2+, or Ag+. These metal ions can be easily removed from the mononuclear metallomacrocycles, and, for example, the metal-free tetraoxime ligand was obtained in 90% yield when Fe2+ was used as the template. It would appear that this one-pot, metal-template Pd2+ cyclization efficiently proceeds through continual metal-mediated oxime exchange reactions. Interestingly, which does not afford any cyclized products, formed a 1:1 complex with the macrocyclic ligand. The molecular structures of the metal-free ligand, its 1:1 metal complexes with Fe2+, Ni2+, Cu2+, Pd2+, and Ag+, and a dinuclear complex with Ag+ were fully determined by single-crystal X-ray analyses. UV-visible absorption spectra and cyclic voltammetry measurements of these complexes are also reported.