Abstract:
Coordination chemistry is a powerful method to synthesize supramolecular cages with distinct features that suit specific applications. This work demonstrates the synthesis of discrete, homochiral FeII 2 L3 cages via chirality-driven self-assembly. Specifically, the installation of chirality - at both the vertices and ligand backbones - allows the formation of discrete, homochiral FeII 2 L3 cages of different sizes via stereochemical control of the iron(II) centers. We observed that larger cages require multiple chiral centra (chiral ligands and vertices). In contrast, the formation of smaller cages is stereoselective with solely chiral ligands. The latter cages can also be formed from two chiral subcomponents, but only when they have matching chirality. Single-crystal X-ray diffraction of these smaller FeII 2 L3 cages revealed several non-covalent interactions as a driving force for narcissistic chiral self-sorting. This expected behavior was confirmed utilizing the shorter ligands in racemic form, yielding discrete, homochiral FeII 2 L3 cages formed in enantiomeric pairs.
摘要:
配位化学是合成具有适合特定应用的独特特征的超分子笼的强大方法。这项工作展示了离散的合成,同向FeII2L3笼通过手性驱动的自组装。具体来说,手性的安装-在顶点和配体骨架-允许形成离散的,通过对铁(II)中心的立体化学控制,具有不同大小的纯手性FeII2L3笼子。我们观察到较大的笼需要多个手性中心(手性配体和顶点)。相比之下,较小的笼的形成是立体选择性的,只有手性配体。后者的笼子也可以由两个手性亚组分形成,但只有当他们反对匹配的手性时。这些较小的FeII2L3笼的单晶X射线衍射揭示了几种非共价相互作用,称为自恋性手性自分选的驱动力。利用外消旋形式的较短配体证实了这种预期的行为,屈服离散,对映体对中的同手性FeII2L3笼。