Department of Chemistry, University of British Columbia, Vancouver, Canada.
Chemistry. 2012 Oct 22;18(43):13712-21. doi: 10.1002/chem.201201536. Epub 2012 Sep 20.
We report a template-free strategy based on steric repulsion for the isolation of discrete columnar aggregates of macrocycles. Specifically, introduction of sterically-demanding trityl-derived substituents at the periphery of Pt(4) Schiff base macrocycles limits the otherwise infinite one-dimensional columnar aggregation to discrete tetrameric and hexameric assemblies. Single crystal X-ray diffraction studies of these compounds reveal discrete nanotubes of finite length that pack inefficiently resulting in three-dimensional networks of interconnected void space. The discrete assemblies were studied by N(2) adsorption and show enhanced surface area when stacked. In the absence of bulky substituents the macrocycles are nonporous. This strategy for engineering discrete supramolecular macrocyclic aggregates may be generalized to other columnar assembling systems.
我们报告了一种基于空间排斥的无模板策略，用于分离大环的离散柱状聚集体。具体来说，在 Pt(4)席夫碱大环的外围引入空间位阻大的三苯甲基衍生取代基，将原本无限的一维柱状聚集限制为离散的四聚体和六聚体组装体。这些化合物的单晶 X 射线衍射研究揭示了离散的有限长度纳米管，它们的堆积效率低，导致相互连接的空隙的三维网络。通过氮气吸附研究了这些离散组装体，发现它们在堆积时具有增强的比表面积。在没有大体积取代基的情况下，大环是无孔的。这种用于工程离散超分子大环聚合体的策略可能会推广到其他柱状组装体系。
