Modifying the internal substituents of self-assembled cages controls their molecular recognition and optical properties
Modifying the internal substituents of self-assembled cages controls their molecular recognition and optical properties
复制标题
修饰自组装笼的内部取代基可控制其分子识别和光学性质
DOI：
10.1039/d2dt01451c
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发表时间：
2022
影响因子：
4
通讯作者：
Hooley, Richard J.
中科院分区：
文献类型：
--
作者：
Woods, Connor Z.;Wu, Hoi-Ting;Ngai, Courtney;da Camara, Bryce;Julian, Ryan R.;Hooley, Richard J.
以2,7-二溴咔唑配体为支架，将6个官能团定向到笼内，可合成具有可变内部功能的自组装Fe4L6笼配合物。乙基硫甲醚和乙基二甲氨基都可以加入。该笼具有强的配体中心荧光发射和广泛的客体结合特性。中性有机客体的共包封有利于较大的、非功能化的笼腔，而硫醚笼具有更大的空间阻碍腔，有利于1:1客体结合。CH3CN的结合亲和可达106 M−1。二甲胺笼更复杂，因为内部胺显示部分质子化，可以被胺碱去质子化。这种胺笼对广泛的中性有机底物具有亲和性，其亲和性和化学计量学与类似大小的硫醚笼相当。这些物种表明，配体主链的简单变化可以改变自组装宿主腔的功能数量和类型，这将在仿生传感、催化和分子识别中得到应用。
Self-assembled Fe4L6 cage complexes with variable internal functions can be synthesized from a 2,7-dibromocarbazole ligand scaffold, which orients six functional groups to the cage interior. Both ethylthiomethylether and ethyldimethylamino groups can be incorporated. The cages show strong ligand-centered fluorescence emission and a broad range of guest binding properties. Coencapsulation of neutral organic guests is favored in the larger, unfunctionalized cage cavity, whereas the thioether cage has a more sterically hindered cavity that favors 1 : 1 guest binding. Binding affinities up to 106 M−1 in CH3CN are seen. The dimethylamino cage is more complex, as the internal amines display partial protonation and can be deprotonated by amine bases. This amine cage displays affinity for a broad range of neutral organic substrates, with affinities and stoichiometries comparable to that of the similarly sized thioether cage. These species show that simple variations in ligand backbone allow variations in the number and type of functions that can be displayed towards the cavity of self-assembled hosts, which will have applications in biomimetic sensing, catalysis and molecular recognition.