School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
Molecules. 2022 Sep 3;27(17):5689. doi: 10.3390/molecules27175689.
A series of fluorescent calix[4]arene scaffolds bearing electron-rich carbazole moiety conjugated at the lower rim have been prepared. Studies of the fluorescence quenching in the presence of the N-methyl pyridinium guest revealed that the electronic properties of the distal phenolic ring play a major role in the host-guest complexation. In particular, placing an electron-donating piperidine fragment at that ring significantly increased the host-guest interactions, while introducing the same fragment into the proximal phenolic ring weakened the fluorescence response. These results suggest that the dominant interactions between the guest and calixarene cavity involve the oxygen-depleted fluorophore-bearing aromatic ring and not the more electron-rich unsubstituted phenolic fragments.
一系列荧光杯[4]芳烃支架，在较低的边缘连接有富电子咔唑部分，已经被制备出来。在存在 N-甲基吡啶鎓客体的情况下，荧光猝灭的研究表明，远端酚环的电子性质在主客体络合中起着重要作用。特别是，在该环上放置一个供电子的哌啶片段会显著增加主客体相互作用，而在近端酚环中引入相同的片段会削弱荧光响应。这些结果表明，客体和杯芳烃空腔之间的主要相互作用涉及缺电子荧光团的芳香环，而不是更富电子的未取代酚片段。
