Department of Organic Chemistry, Vilnius University , Naugarduko 24, LT-03225 Vilnius, Lithuania.
Center for Analysis and Synthesis, Department of Chemistry, Lund University , P.O. Box 124, SE-22100, Lund, Sweden.
J Am Chem Soc. 2015 Aug 26;137(33):10536-46. doi: 10.1021/jacs.5b03160. Epub 2015 May 21.
The formation of an unprecedented decameric capsule in carbon disulfide, held together by the combination of double and triple hydrogen bonds between isocytosine units embedded in an enantiomerically pure bicyclic framework is reported. The aggregation occurs via symmetry breaking of the enantiopure intrinsically C2-symmetric monomer brought about by solvent, induced tautomerization of the hydrogen-bonding unit. We show that the topology of the aggregate is responsive to the solvent in which the assembly takes place. In this study we demonstrate that in carbon disulfide the chiral decameric cavity aggregate consisting of three forms of the same monomer, differing in their hydrogen bonding to each other is selectively formed, representing a tube-like structure capped with two C2-symmetric monomers. The large cylindrical cavity produced selectively accommodates one partially solvated C60 molecule, and molecular dynamic simulations revealed the special role of the solvent in the inclusion mechanism. The strategy described herein represents the first step toward the creation of a new class of hydrogen-bonded tubular objects from only one small symmetric building block by solvent-responsive aggregation.
本文报道了一种前所未有的十聚体胶囊在二硫化碳中的形成，该胶囊由嵌入手性纯双环骨架中的异胞嘧啶单元之间的双氢键和三氢键组合而成。通过溶剂诱导氢键单元的互变异构，打破手性纯单体的内禀 C2 对称，从而引发聚集。我们表明，聚集的拓扑结构对组装所发生的溶剂具有响应性。在这项研究中，我们证明在二硫化碳中，由三种相同单体组成的手性十聚体空腔聚集物选择性形成，这些单体在彼此之间的氢键上存在差异，代表了一种带有两个 C2 对称单体帽的管状结构。选择性形成的大圆柱形空腔容纳了一个部分溶剂化的 C60 分子，分子动力学模拟揭示了溶剂在包合机制中的特殊作用。本文所述的策略代表了通过溶剂响应聚集，仅使用一个小对称构建块来创建新型氢键管状物体的第一步。
