Recognition of silver cations by a cucurbit[8]uril-induced supramolecular crown ether

Abstract

The host-guest interaction of cucurbit[8]uril (Q[8]) with a synthesized guest molecule, consisting of naphthalene and viologen moieties bridged by a carbon oxygen chain, was investigated by (1)H NMR and UV-Vis spectroscopy. The results indicated the formation of an inclusion complex in a ratio of 1 : 1 with a moderate association constant of Ka = (1.1 ± 0.2) × 10(6) L mol(-1). The formation of this special complex is driven by the markedly enhanced charge-transfer interaction between the electron-rich and electron-deficient guest molecule inside the hydrophobic cavity of Q[8], while the carbon oxygen chain stays outside of Q[8] to form a supramolecular crown ether. Screening of the metal cation substrate suggested that the inclusion complex recognizes Ag(+) ions with high selectivity, as shown by UV-Vis spectroscopy.

Study on the interactions between melamine-cored Schiff bases with cucurbit[n]urils of different sizes and its application in detecting silver ions

“…Since Q [7] and TBT form a host-guest complex, the carboxyl group at the end of TBT and the carbonyl group of the Q [7] still have a strong ability to coordinate with metals. Therefore, Q [7]-TBT is selected for the detection of silver ions (Ag + ) [32,33].…”

Recognition of Lanthanide Metal Cations by t‐DSMI@Alkyl‐Substituted Cucurbit[6]uril Probes

“…Introducing metal cations (M n + ) into Q[n]-based host-guest interaction systems or guest molecules (G) into Q [n]-M n + coordination systems can result in the formation of stimuli-responsive QGM systems. Such systems may potentially be used in wastewater treatment, [13,14] drug delivery, [15][16][17] catalytic processes, [18,19] or the recognition of metal cations, [20,21] thereby establishing a new branch of Q[n] chemistry. This has prompted us to focus in particular on research concerning the recognition of metal cations using Q[n]-based host-guest interaction systems.…”

Identification of Ferric Ions Using a Palmatine@Q[8] Fluorescent Probe

“…For example, a fluorescence probe comprising cucurbit[7]uril (Q[7]) and the chloride salt of N‐(2‐benzimidazolylmethyl)‐N,N‐bis(2‐pyridylmethyl)‐amine cations can recognise Cd 2+ and Zn 2+ cations, and this is accompanied by enhanced fluorescence . Furthermore, a Q[8]‐based charge‐transfer‐type inclusion complex exhibited unique selectivity for Ag + ions . and a fluorescent probe comprising a twisted cucurbit[14]uril (tQ[14]) and thiazole orange (TO), can respond to Hg 2+ , Ba 2+ , and Pb 2+ cations under different pH conditions …”