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Cinchonine (+Ccn) and cinchonidine (−Ccn) are quinoline alkaloid drugs, which are found in natural products of cinchona bark and are used as specific drugs for treating malaria. As a pair of chiral enantiomers, they show different biological activities and performances in pharmacological applications. In this work, we prepared a fluorescence sensor based on a Zn coordination polymer for the sensitive and selective detection of the above enantiomers, namely, [Zn(PT)(H2O)2]n (IMU-Zn1) (H2PT = 5-(5-pyrimidyl)-1,3-benzenedicarboxylic acid). +Ccn and −Ccn had a "turn-on" effect on the fluorescence of IMU-Zn1, and the ratio of their fluorescence enhancement rate reached 2.22, and the limits of detection (LOD) for +Ccn and −Ccn were 2.10 μM and 1.90 μM, respectively. In addition, infrared spectroscopy, 1HNMR spectroscopy, X-ray powder diffraction, fluorescence lifetime, Gaussian calculations, and other characterization methods were used to explore the mechanism of fluorescence enhancement. The results showed that there was a photoelectron transfer process and there were electrostatic interactions between +Ccn and IMU-Zn1. The photoelectron transfer process, the electrostatic interactions, and the stronger hydrogen-bonding interactions between −Ccn and IMU-Zn1 are responsible for a more pronounced fluorescence enhancement. This work provides an alternative strategy for the identification of chiral enantiomers using light-emitting coordination polymers as fluorescent probes. [ABSTRACT FROM AUTHOR]

Based on 3‐(2,4‐dicarboxylphenyl)‐6‐carboxylpyridine ligand (H3dpcp), a lanthanide metal–organic framework with the porous three‐dimensional structure was successfully synthesized, namely, [Eu (dpcp)(H2O)]n (1). The experimental results indicated that complex 1 exhibited stable luminescence in the range of pH = 2–11 in aqueous solution. It is noteworthy that complex 1 could recognize tryptophan (Trp) and trans, trans‐muconic acid (tt‐MA) molecules through the fluorescence quenching effect, and showed high sensitivity, selectivity, recoverability, anti‐interference, and low detection limits for the identification of Trp and tt‐MA in aqueous solution. In addition, the fluorescence mechanisms of complex 1 for sensing of tt‐MA and Trp were elucidated in detail. [ABSTRACT FROM AUTHOR]

Cucurbit[6]uril‐derivatized vinyl monomer (cucurbit[6]uril methacrylate) was synthesized. Acrylic acid (AA) was used as the comonomer for copolymerization with the cucurbit[6]uril‐derivatized monomer. A series of copolymers of poly(acrylic acid‐co‐cucurbit[6]uril methacrylate) (PAA‐co‐CB[6]MA) were synthesized by free radical polymerization. The cucurbit[6]uril‐derivatized monomer and PAA‐co‐CB[6]MA copolymers were characterized by 1H NMR spectra, high‐resolution mass spectroscopy and gel permeation chromatography. The solution behavior was examined using UV–visible spectroscopy and dynamic light scattering. The PAA‐co‐CB[6]MA showed an upper critical solution temperature (UCST) in water. The UCST‐type thermoresponsive behavior of these CB[6]‐derivatized copolymers was highly dependent on the composition of the copolymer. For the same type of copolymer, changes in its composition gave rise to different UCSTs. Additionally, the PAA‐co‐CB[6]MA copolymers were successful in trapping azocarmine B. The stimuli‐responsive release of encapsulated azocarmine B was achieved by a combination of temperature and pH value stimuli. According to the results, the novel PAA‐co‐CB[6]MA copolymers can be used as carriers. © 2021 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

ABSTRACT Based on 4‐([2,2′:6′,2″‐terpyridin]‐4′‐yl) benzoic acid ligand (Htpba), a fluorescent lanthanide coordination polymer was successfully synthesized, namely, [Eu (tpba)3]n (1). The single‐crystal diffraction analysis shows that Eu3+ ions in complex 1 are alternately connected with tpba3− ligands to form a one‐dimensional chain structure, which further constitutes a three‐dimensional supramolecular architecture through the π···π interactions. Complex 1 demonstrated excellent stability of thermogravimetry; and displayed good fluorescence intensity in aqueous solution with a wide pH range. In this work, complex 1 was used as a fluorescence sensor for the detection of jatrorrhizine molecule (JAT). It was found that complex 1 had high sensitivity with the detection limit of 1.02 × 10−8 M, and simultaneously displayed specific selectivity and reutilization for the exploration of JAT molecule. The static quenching, the absorption competition, the electrostatic interactions, and the photo‐induced electron transfer process are responsible for the recognition mechanism of complex 1 with sensing JAT. It is worth mentioning that a fluorescent film based on complex 1 and a light‐emitting diode device coated with the powder of complex 1 were successfully fabricated, which could rapidly recognize JAT molecule with the naked eye further. [ABSTRACT FROM AUTHOR]