PDF(Pubmed)
Abstract：
Metal-organic cages (MOCs) are popular host architectures assembled from ligands and metal ions/nodes. Assembling structurally complex, low-symmetry MOCs with anisotropic cavities can be limited by the formation of statistical isomer libraries. We set out to investigate the use of primary coordination-sphere engineering (CSE) to bias isomer selectivity within homo- and heteroleptic Pdn L2n cages. Unexpected differences in selectivities between alternative donor groups led us to recognise the significant impact of the second coordination sphere on isomer stabilities. From this, molecular-level insight into the origins of selectivity between cis and trans diastereoisomers was gained, highlighting the importance of both host-guest and host-solvent interactions, in addition to ligand design. This detailed understanding allows precision engineering of low-symmetry MOC assemblies without wholesale redesign of the ligand framework, and fundamentally provides a theoretical scaffold for the development of stimuli-responsive, shape-shifting MOCs.
摘要：
金属-有机笼(MOC)是由配体和金属离子/节点组装的流行的宿主架构。组装结构复杂，具有各向异性腔的低对称性MOCs可能受到统计异构体库的形成的限制。我们着手研究使用初级配位球工程（CSE）来偏向同位和异位PdnL2n笼中的异构体选择性。替代供体基团之间选择性的意外差异使我们认识到第二配位球对异构体稳定性的显着影响。由此,获得了分子水平对顺式和反式非对映异构体之间选择性起源的见解，强调宿主-客体和宿主-溶剂相互作用的重要性，除了配体设计。这种详细的理解允许低对称MOC组件的精确工程，而无需大规模重新设计配体框架，从根本上为刺激反应的发展提供了理论基础，变形MOCs。
