Supramolecular macrocycles reversibly assembled by Te(…)O chalcogen bonding.
Supramolecular macrocycles reversibly assembled by Te(…)O chalcogen bonding.
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DOI：
10.1038/ncomms11299
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发表时间：
2016-04-19
影响因子：
16.6
通讯作者：
Vargas-Baca I
中科院分区：
文献类型：
--
作者：
Ho PC;Szydlowski P;Sinclair J;Elder PJ;Kübel J;Gendy C;Lee LM;Jenkins H;Britten JF;Morim DR;Vargas-Baca I
具有重主族元素的有机分子经常与富电子中心形成超分子连接。这种相互作用的一种特殊情况是卤素键合。大多数对这种现象的研究都是关于二聚体或无限延伸的结构（聚合物和晶格），但定义明确的环状结构仍然难以捉摸。在这里，我们提出了低聚物聚集的杂环连接的硫族中心的相互作用，并表现为真正的大环物种。3-甲基-5-苯基-1，2-碲唑2-氧化物分子组装成各种超分子聚集体，包括环状四聚体和六聚体，以及螺旋聚合物。在所有这些聚集体中，结构单元通过Te... O-N桥连接。核磁共振光谱实验表明，这两种类型的环状聚集体在溶液中是持久的。这些自组装结构与过渡金属离子形成配位络合物，充当富勒烯受体并在晶体中容纳小分子。 类似于卤素键合，较重的硫属元素能够与富电子位点形成超分子连接。在这里，作者表明，这些力可以允许形成定义明确的环状结构，这些环状结构在溶液中是稳定的，并且能够形成主客体复合物。
Organic molecules with heavy main-group elements frequently form supramolecular links to electron-rich centres. One particular case of such interactions is halogen bonding. Most studies of this phenomenon have been concerned with either dimers or infinitely extended structures (polymers and lattices) but well-defined cyclic structures remain elusive. Here we present oligomeric aggregates of heterocycles that are linked by chalcogen-centered interactions and behave as genuine macrocyclic species. The molecules of 3-methyl-5-phenyl-1,2-tellurazole 2-oxide assemble a variety of supramolecular aggregates that includes cyclic tetramers and hexamers, as well as a helical polymer. In all these aggregates, the building blocks are connected by Te…O–N bridges. Nuclear magnetic resonance spectroscopic experiments demonstrate that the two types of annular aggregates are persistent in solution. These self-assembled structures form coordination complexes with transition-metal ions, act as fullerene receptors and host small molecules in a crystal. Similarly to halogen bonding, the heavier chalcogens are capable of forming supramolecular links with electron rich sites. Here, the authors show that these forces can allow the formation of well-defined cyclic structures that are stable in solution and are capable of forming host-guest complexes.