Department of Chemistry, College of Science, United Arab Emirates University, Al Ain, 15551, United Arab Emirates.
National Water and Energy Center, United Arab Emirates University, Al Ain, 15551, United Arab Emirates.
Photochem Photobiol. 2022 Jul;98(4):754-762. doi: 10.1111/php.13571. Epub 2021 Dec 19.
Host-guest complexation of small heterocyclic (guest) and macrocyclic cavitands (hosts) organic molecules is still to date a very popular, inexpensive approach that bypasses the burdens of conventional covalent synthesis. Understanding the selection criteria of these chemicals is crucial to the design and potential applications of their supramolecular assemblies. This review surveys examples within the last 15 years (2005-2020) of supramolecular complexes in which the interacting photoinduced electron transfer (PET)-based chromophore and quencher fragments are commonly used in the market with reported CAS numbers. It appears from this survey that the supramolecular effects can be directed to specifically disrupt PET when the nonemissive macrocycles separately encapsulate the fluorescent acceptor or donor molecules, among other specific factors, such as when inducing conformational changes or pK shift of the donor. On the contrary, synergetic encapsulation of both donor and acceptor molecules, formation of ternary self-assembly at the rim or encapsulation of one component while grafting the other onto the macrocycle, among other specific factors such as the modulation of the excited-state structure of donor, will lead to the enhancement of PET process. In the event the donor or acceptor molecules have multitopic structures, the PET process can repeatedly be switched on and off. It is generally concluded that understanding the criteria for the combination of these available products for the purpose of manipulating their PET efficiency should pave the way for the facile alternative generation of new noncovalently bonded host-guest supramolecular assemblies with a more specific design tailored for more advanced, diverse and economic applications such as chemical sensing, molecular gates, drug delivery and biolabeling.
主体-客体络合的小分子杂环（客体）和大环空穴（主体）有机分子仍然是一种非常流行的、廉价的方法，可以避免传统共价合成的负担。了解这些化学物质的选择标准对于它们的超分子组装的设计和潜在应用至关重要。本综述调查了过去 15 年（2005-2020 年）中基于光诱导电子转移（PET）的相互作用发色团和猝灭剂片段的超分子复合物的例子，这些片段在市场上通常使用带有报告 CAS 编号的化合物。从这项调查中可以看出，当非发光大环分别封装荧光受体或供体分子时，超分子效应可以被定向专门破坏 PET，这是由于其他特定因素，如诱导供体的构象变化或 pK 转移。相反，当同时包封供体和受体分子、在边缘形成三元自组装、包封一个组件同时将另一个接枝到大环上，以及其他特定因素，如供体的激发态结构的调制，将导致 PET 过程增强。在供体或受体分子具有多价结构的情况下，PET 过程可以反复开启和关闭。一般来说，理解这些现有产品组合的标准，目的是操纵它们的 PET 效率，应该为更简单地生成具有更特定设计的新型非共价键合主体-客体超分子组装铺平道路，以适应更先进、更多样化和更经济的应用，如化学传感、分子门、药物传递和生物标记。
