p-tert-Butylcalix[8]arene: an extremely versatile platform for cluster formation.
p-tert-Butylcalix[8]arene: an extremely versatile platform for cluster formation.
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DOI：
10.1002/chem.201202644
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发表时间：
2012-12
期刊：
影响因子：
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通讯作者：
Stephanie M. Taylor;S. Sanz;R. McIntosh;C. Beavers;S. Teat;E. Brechin;S. Dalgarno
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文献类型：
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作者：
Stephanie M. Taylor;S. Sanz;R. McIntosh;C. Beavers;S. Teat;E. Brechin;S. Dalgarno
对叔丁基杯[4]芳烃是一种碗状分子，能够在不同的实验条件下形成一系列多核金属簇合物。对叔丁基杯[8]芳烃(TBC[8])是一种更加灵活的类似物，以前已被证明可以形成单核和双核的稀土(Ln)金属络合物。后者(簇)基序是常见的，涉及杯芳烃采用近双锥构象，这一特征表明它可能被用作形成更大的多核稀土簇合物的一种组装节点。通过改变实验条件，可以得到Ln(1)、Ln(2)、Ln(4)、Ln(5)、Ln(6)、Ln(7)和Ln(8)的配合物，所有的多金属团簇都含有共同的双核稀土碎片。仔细观察多金属团簇的结构发现，除了一个(Ln(8))外，所有的Ln(8)实际上都是以金属八面体或八面体的积木为基础的，最终产物的一致性和大小取决于溶液的碱性和TbC[8]配体的去质子化水平。这既证明了配体对加入额外金属中心的多功能性，也表明了对所得到的可互换稀土中心的组装体的磁性进行剪裁的相关含义。
p-tert-Butylcalix[4]arene is a bowl-shaped molecule capable of forming a range of polynuclear metal clusters under different experimental conditions. p-tert-Butylcalix[8]arene (TBC[8]) is a significantly more flexible analogue that has previously been shown to form mono- and binuclear lanthanide (Ln) metal complexes. The latter (cluster) motif is commonly observed and involves the calixarene adopting a near double-cone conformation, features of which suggested that it may be exploited as a type of assembly node in the formation of larger polynuclear lanthanide clusters. Variation in the experimental conditions employed for this system provides access to Ln(1), Ln(2), Ln(4), Ln(5), Ln(6), Ln(7) and Ln(8) complexes, with all polymetallic clusters containing the common binuclear lanthanide fragment. Closer inspection of the structures of the polymetallic clusters reveals that all but one (Ln(8)) are in fact based on metal octahedra or the building blocks of octahedra, with the identity and size of the final product dependent upon the basicity of the solution and the deprotonation level of the TBC[8] ligand. This demonstrates both the versatility of the ligand towards incorporation of additional metal centres, and the associated implications for tailoring the magnetic properties of the resulting assemblies in which lanthanide centres may be interchanged.