Abstract:
Incorporating chiral elements in host-guest systems currently attracts much attention because of the major impact such structures may have in a wide range of applications, from pharmaceuticals to materials science and beyond. Moreover, the development of multi-responsive and -functional systems is highly desirable since they offer numerous benefits. In this context, we describe herein the construction of a metal-driven self-assembled cage that associates a chiral truxene-based ligand and a bis-ruthenium complex. The maximum separation between both facing chiral units in the assembly is fixed by the intermetallic distance within the lateral bis-ruthenium complex (8.4 Å). The resulting chiral cavity was shown to encapsulate polyaromatic guest molecules, but also to afford a chiral triply interlocked [2]catenane structure. The formation of the latter occurs at high concentration, while its disassembly could be achieved by the addition of a planar achiral molecule. Interestingly the planar achiral molecule exhibits induced circular dichroism signature when trapped within the chiral cavity, thus demonstrating the ability of the cage to induce supramolecular chirogenesis.
摘要:
在主客体系统中加入手性元素目前备受关注,这是由这种结构可能对广泛的应用产生的重大影响造成的,从制药到材料科学等等。此外,多响应和功能系统的发展是非常可取的,因为它们提供了许多好处。在这种情况下,本文中,我们描述了金属驱动的自组装笼的构造,其将手性基于辉石的配体和双钌络合物相关联。组件中两个面对的手性单元之间的最大间距由横向双钌络合物内的金属间距离(8.4进行)固定。所产生的手性腔被证明可以封装多芳族客体分子,而且还提供了手性三互锁[2]catenane结构。后者的形成发生在高浓度,而其分解可以通过添加平面非手性分子来实现。有趣的是,当被捕获在手性腔内时,后者表现出诱导的圆二色性特征,证明了诱导超分子体外发生的笼子能力。