Selective supramolecular bindings for stepwise signal output

The design and construction of functional supramolecular systems capable of digital information processing is very important. In this work, we synthesized two fluorescent guest compounds (OVN and MVN) for supramolecular bindings at different sites with cucurbit[7]uril (CB7) and α-cyclodextrin (α-CD). The selective host–guest formation was employed to control the systems’ fluorescent signal for different-mode performances. The structural characterizations were conducted by ¹H NMR, HRMS, and 2D NOESY ¹H NMR spectroscopy. Specifically, the selective supramolecular bindings of CB7 and α-CD will cause a stepwise variation of the fluorescent signal output in OVN guest system. This signal can also be stepwise reset by introduction of different competing substances. On the other hand, supramolecular bindings can only lead to a binary signal change in MVN guest system.