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Under the synergistic effects of protonation and deprotonation, a light-activated fluorescent probe (UV-SP) exhibited “cycle-reversible intramolecular charge transfer (ICT)” for different pH after activation by UV light, resulting in emission of multiple ratio fluorescent signals (FI563/FI595 and FI664/FI595). Based on these kinds of response signals, UV-SP can specifically monitor the cycle-reversible trace change of intracellular pH caused by UV radiation. More importantly, according to the stable and invariant multiple ratio fluorescent signals, UV-SP can sort cells entering programmed death. [ABSTRACT FROM AUTHOR]

The title compound, C6H9N2O2+·Cl−·C6H8N2O2·H2O, contains one 2-(3-methyl-1 H-imidazol-3-ium-1-yl)acetate inner salt molecule, one 1-carboxymethyl-3-methyl-1 H-imidazol-3-ium cation, one chloride ion and one water molecule. In the extended structure, chloride anions and water molecules are linked via O-H...Cl hydrogen bonds, forming an infinite one-dimensional chain. The chloride anions are also linked by two weak C-H...Cl interactions to neighbouring methylene groups and imidazole rings. Two imidazolium moieties form a homoconjugated cation through a strong and asymmetric O-H...O hydrogen bond of 2.472 (2) Å. The IR spectrum shows a continuous D-type absorption in the region below 1300 cm−1 and is different to that of 1-carboxymethyl-3-methylimidazolium chloride [Xuan, Wang & Xue (2012). Spectrochim. Acta Part A, 96, 436-443]. [ABSTRACT FROM AUTHOR]

Abstract: The structures, vibrational frequencies, infrared and Raman intensities of hexafluorophosphate anion (PF6 −) and M+PF6 − (M+ =Li+, Na+, K+, Rb+ and Cs+) ion pairs have been studied by ab initio calculations. It is shown that the tridentate coordination of cation by PF6 − is the most stable structure in gas phase. The vibrational spectroscopies of the most stable geometries were calculated and the changes in band position were used to probe the ion associations. [Copyright &y& Elsevier]

Abstract: Solid polymer electrolytes are potentially useful electrolytes to be applied in high-energy batteries. In the present work, a novel polymer electrolyte, polyethylene oxide (PEO)–NaSCN–AlCl3, was prepared and investigated by FT-IR spectroscopic techniques. Based on the FT-IR data, the bands in the CN stretching envelope have been assigned and the effect of AlCl3 on ion–ion and ion–polymer interactions in the polymer electrolyte has been examined. It is shown that the Lewis acid–base interaction of AlCl3 with SCN1− leads to the formation of the complex anions AlCl3SCN− and Al2Cl6SCN−, depending on the content of AlCl3 and/or NaSCN in PEO; the preferential interactions of AlCl3 with crystal complex P(EO)3NaSCN occur in PEO–NaSCN–AlCl3 electrolytes; the AlCl3–NaSCN complex anions can play a plasticization role in PEO–NaSCN–AlCl3 electrolyte, and are expected to be a important factor to improve the conductivity and to enhance the cation transference number. In addition, the interactions between AlCl3 and ether oxygen of PEO were analyzed, and their effect on ionic association was also discussed. [Copyright &y& Elsevier]

Two isostructural, three-dimensional, interpenetrated amino-functionalized Metal-Organic Frameworks (Co-2AIN-MOF and Cd-2AIN-MOF) based on 2-aminoisonicotinic acid (2AIN) were synthesized, structurally characterized and determined. Based on the PXRD analysis, the solvent exchange hardly changed their framework structure, and the samples fully activated by methanol can be achieved and examined by infrared spectroscopy. Due to the presence of the carbonyl group and free amino groups in the pore of the framework, the NH 3 uptakes of Co-2AIN-MOF and Cd-2AIN-MOF are 11.70 and 13.81 mmol/g and at 1 bar, respectively. In-situ Infrared spectroscopy and DFT calculations revealed the different adsorption sites and processes between Co-2AIN-MOF and Cd-2AIN-MOF., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A Pickering emulsion is a natural microreactor for interfacial catalysis in which an emulsifier is critical. Recently, a metal-organic framework (MOF) has attracted attention to emulsify water-organic mixtures for constructing a Pickering emulsion. However, a few stimuli-responsive Pickering emulsions based on MOFs have been reported, and the MOF emulsifiers cannot be regenerated at room temperature. Herein, the Zr-MOF with a rodlike morphology is synthesized using ionic liquid as a modulator and then modified with n -(trimethoxysilylpropyl)imidazole (C 3 im) to prepare a series of functionalized Zr-MOFs (MOF-C 3 im). It is found that MOF-C 3 im is an excellent emulsifier to construct stable and CO 2 -responsive Pickering emulsions even at low content (>0.20 wt %). Notably, the emulsification and demulsification of the emulsions can be easily and reversibly switched by bubbling of CO 2 and N 2 alternatively at room temperature because CO 2 and imidazole molecules anchored on the Zr-MOF underwent a reversible acid-base reaction, resulting in an obvious change in the wettability of the emulsifier. As a proof of concept, the reduction reactions of nitrobenzene have been successfully carried out in these Pickering emulsions, demonstrating the efficient integration as a microreactor for chemical reaction, product separation, and emulsifier recycling under ambient conditions. This strategy provides an innovative option to develop stimulus-responsive Pickering emulsions for sustainable chemical processes.

In recent years, light-responsive molecules have been incorporated in metal-organic frameworks (MOFs) to fabricate light-responsive intelligent devices, where reversible isomerization of the guest molecules in the nanopores is crucial. However, how to design a porous environment of MOFs to achieve a reversible isomerization remains unknown until now. In this work, donor-acceptor Stenhouse adducts (DASAs), a new kind of visible light responsive compound, were confined in the nanopores of different MOFs to study their isomerization upon visible-light irradiation/mild heating. We found that the polarity of the pore environment is the key to control the reversibility of isomerization of such guest molecules. Under the guidance of this principle, MIL-53(Al) was screened to investigate the proton conductivity and switching performance of the DASA-confined MOF. The proton conductance was up to 0.013 S cm -1 at 80 °C and 98 % RH, and at least 30 switching cycles were achieved thanks to the Grotthuss-type mechanism and the low polarity of MIL-53(Al) pore environment., (© 2023 Wiley-VCH GmbH.)

Beta-cyclodextrin (beta-CD) is difficult to dissolve in water and in many common solvents and searching for the proper solvents is the key step to expand its application. In this work, six kinds of hydrophilic ionic liquids 1-n-butyl-3-methylimidazolium chloride, 1-(2-hydroxyethyl)-3-methylimidazolium chloride, 1-allyl-3-methylimidazolium chloride, 1-n-butyl-3-methylimidazolium dicyanamide, 1-(2-hydroxyethyl)-3- methylimidazolium dicyanamide and 1-allyl-3-methyl-imidazolium dicyanamide have been prepared. The solubilities of beta-cyclodextrin in these ionic liquids have been determined in the temperature range from 333.2 to 363.2 K with 5 K intervals. The solution thermodynamic parameters of beta-cyclodextrin have been calculated from the solubility data. It was shown that solubility of beta-cyclodextrin was remarkable in ionic liquids, it was as high as 125.0 g in 100 g of [Amim][N(CN)(2)] at 348.2 K. The dissolution process was unfavorable thermodynamically and controlled by the enthalpic term. (1)H NMR and IR spectroscopic measurements were used to study the enhanced dissolution of beta-cyclodextrin in the ionic liquids. The results indicated that 1:1 inclusion complexes were formed between beta-cyclodextrin and imidazolium cations of the ionic liquids. The differences in the solubility of beta-cyclodextrin have been discussed from the interionic interaction between cation and anion of the ionic liquids and the inclusion interaction of the cations of the ionic liquids into the cavities of beta-cyclodextrin. The strength of the interionic interactions was found to be predominant for the dissolution of beta-cyclodextrin. It is expected that such information may find application in the molecular design of the stationary phases in gas chromatography.

The title compound, [Pb(2)(CH(3)COO)(2)(C(7)H(5)O(2))(2)(C(12)H(8)N(2))(2)]·2H(2)O, consists of dimeric units built up around a crystallographic centre of symmetry and two non-coordinating water mol-ecules. Each Pb(II) unit is six-coordinated by a bidentate 1,10-phenanthroline (phen) ligand, a monodentate acetate anion and a bidentate benzoate anion, which also acts as a bridge linking the two Pb(II) atoms. The crystal packing is stabilized by O-H⋯O hydrogen bonds and by π-π inter-actions between the phen rings of neighboring mol-ecules, with a centroid-centroid distance of 3.577 (3) Å.