Detecting Pesticide Dodine by Displacement of Fluorescent Acridine from Cucurbit[10]uril Macrocycle

According to a simple guest-replacement fluorescence turn-on mechanism, we constructed a fluorescent probe system based on cucurbit[10]uril (Q[10]) and protonated acridine (AD) to detect the pesticide dodine (DD). Formation of a homoternary inclusion complex AD₂@Q[10] in both aqueous solution and solid state was studied by means of ¹H NMR spectroscopy and X-ray crystallography. Although AD can emit strong fluorescence in aqueous solution, the homoternary inclusion complex AD₂@Q[10] does not exhibit any fluorescence. Upon the addition of the pesticide DD into the aqueous solution of AD₂@Q[10], the AD molecules in the Q[10] cavity are displaced by the pesticide DD, and strong fluorescence recovers. The fluorescent probe system based on Q[10] and AD provided a wide determination of DD from 0 to 4.0 × 10^-5 mol·L^-1 with a low limit of detection of 1.827 × 10^-6 mol·L^-1. The guest-replacement fluorescence turn-on mechanism is also confirmed by ¹H NMR spectroscopy. Further, the fluorescent probe can directly detect DD residues in real agricultural products, and obvious fluorescence signal was observed under UV irradiation.

A Study of the Interaction between Cucurbit[7]uril and Alkyl Substituted 4-Pyrrolidinopyridinium Salts

The interaction between cucurbit[7]uril (Q[7]) and a series of 4-pyrrolidinopyridinium salts bearing aliphatic substituents at the pyridinium nitrogen, namely 4-(C4H8N)C5H5NRBr, where R = H (C0), Et (C2), n-butyl (C4), n-hexyl (C6), has been studied in aqueous solution by 1H NMR spectroscopy, electronic absorption spectroscopy, and mass spectrometry.

Emission enhancement of cationic tetraphenylethylene derivatives by encapsulation in a cucurbit[10]uril host in water

Encapsulation of cationic tetraphenylethylene guests in a cucurbit[10]uril host in water results in strong emission enhancement of these guests since the host–guest interaction caused restriction of intramolecular rotation.

Yttrium and lanthanide (Ln = La and Gd) complexes with cucurbit[10]uril: crystals transforming from supramolecular frameworks to coordination nanotubes

Yttrium and lanthanide complexes with cucurbit[10]uril have been investigated with crystals transforming from supramolecular structures to coordination nanotubes being revealed.

Supramolecular assemblies controlled by cucurbit[n]uril size (n = 6, 7, 8 and 10)

The differing cavity size of the Q[n] determines the binding interactions between the benzyl substituted 4-pyrrolidinopyridinium salt and each Q[n]. Single crystal X-ray diffraction of the guest as well as two host–guest complexes is reported.