Gated, Selective Anion Exchange in Functionalized Self‐Assembled Cage Complexes
Gated, Selective Anion Exchange in Functionalized Self‐Assembled Cage Complexes
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功能化自组装笼状复合物中的门控选择性阴离子交换
DOI：
10.1002/chem.202203588
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Hooley, Richard J.
中科院分区：
文献类型：
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作者：
da Camara, Bryce;Ziv, Noa Bar;Carta, Veronica;Mota Orozco, Gabriela A.;Wu, Hoi‐Ting;Julian, Ryan R.;Hooley, Richard J.
将官能团包埋到Zn4L4自组装笼的外部允许阴离子结合的门控控制。虽然未官能化的笼在配体中含有可以自由旋转的芳基，但连接惰性官能团产生了“门挡”，防止旋转并减缓了客体交换速率，即使主体空腔的内部结构相同。对阴离子交换的影响是微妙的，取决于多种因素，包括阴离子大小，离去阴离子的性质，以及侧基的吸电子能力和空间体积。发生多种交换机制，并且外部基团的性质控制缔合和解离交换过程：这些庞大的基团影响阴离子进出，为交换引入额外的选择性层。微小的变化可以产生巨大的影响：在相同大小的空腔之间，类似于PF6−和SbF6−的阴离子的亲和力可以变化多达400倍。
Appending functional groups to the exterior of Zn4L4self‐assembled cages allows gated control of anion binding. While the unfunctionalized cages contain aryl groups in the ligand that can freely rotate, attaching inert functional groups creates a “doorstop”, preventing rotation and slowing the guest exchange rate, even though the interiors of the host cavities are identically structured. The effects on anion exchange are subtle and depend on multiple factors, including anion size, the nature of the leaving anion, and the electron‐withdrawing ability and steric bulk of the pendant groups. Multiple exchange mechanisms occur, and the nature of the external groups controls associative and dissociative exchange processes: these bulky groups affect both anion egress and ingress, introducing an extra layer of selectivity to the exchange. Small changes can have large effects: affinities for anions as similar as PF6−and SbF6−can vary by as much as 400‐fold between identically sized cavities.