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The pursuit of a straightforward method to recycle organic dyes from effluents and repurpose them into valuable materials represents a highly sought-after yet huge challenge within the realms of chemistry, environment, and materials science. In this context, we employ a host–guest strategy that leverages the recycling of the rhodamine B molecule within the porous structure of a metal–organic framework to facilitate photothermal conversion. This achievement is realized through the electrostatic interaction, which then gives rise to remarkable selectivity and unparalleled uptake capacity for the cationic rhodamine B molecule. Capitalizing on this approach, the application of a columnar device and membrane technology for efficiently trapping rhodamine B molecules becomes feasible. On account of the aggregation effect resulting from the confined pore structure of the host matrix, the fluorescence emission of the encapsulated RhB molecules is significantly reduced, which consequently enhances the photothermal performance of the hybrid material through nonradiative transition. Moreover, the photothermal conversion achieved showcases a myriad of high-performance applications, including bacterial inhibition against Escherichia coliand seawater desalination.

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 (C3im) to prepare a series of functionalized Zr-MOFs (MOF-C3im). It is found that MOF-C3im is an excellent emulsifier to construct stable and CO2-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 CO2and N2alternatively at room temperature because CO2and 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.

The bimetallic organic–inorganic hybrid complex [Li2Mn3(ipa)4(DMF)4]n(ipa = deprotonated 1,3-isophthalic acid, DMF = N,N′-dimethyl formamide) was synthesized via a solvothermal method and then further calcined at high temperature to prepare a spinel-type lithium manganate (LiMn2O4) cathode under different atmospheres with various calcination conditions. The structure of the complex [Li2Mn3(ipa)4(DMF)4]nwas represented by single-crystal X-ray diffraction (XRD), powder XRD, and thermogravimetric (TG) analysis. The morphology and elements of LiMn2O4were analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of LiMn2O4indicated that the direct calcination in an air atmosphere at 850 °C for 12 h was the optimal synthetic condition. The initial discharge specific capacity can reach 95.9 mA h g–1with an open-circuit voltage of ca. 3.0 V and an upper cutoff voltage of ca. 4.3 V at 0.1 C. The initial discharge-specific capacity of 89.8 mA h g–1at 1 C had a Coulombic efficiency of 95.3%. This was 73 mA h g–1at a high rate of 5 C increasing to 91.6 mA h g–1after returning to 0.1 C. After 500 cycles at 1 C, the system remained at 80.7 mA h g–1with 89.9% of the initial discharge specific capacity. These features exhibit better stability than that of the reported LiCoO2and LiNiO2in battery material for LiMn2O4enforcement.

The nonlinear-optical (NLO) materials with second-harmonic-generation (SHG) response need to crystallize in the noncentrosymmetric space group. It is very difficult to control the synthetic conditions to solely form a noncentrosymmetric phase for the materials with noncentrosymmetric and centrosymmetric conformations. Herein, we found that the temperature and halogen anion play an important role during the formation procedure of the pure noncentrosymmetric or centrosymmetric phase for the halogen-based family of coordination polymers to yield hybrid materials with a phase-matching SHG response as well as inherit the primary excellent photonic property of organic linkers. Our results provide a good choice for the design and construction of novel materials with a particular photonic property.

The unrepaired apurinic/apyrimidinic site (AP site) in mitochondrial DNA (mtDNA) promotes misincorporation of nucleotides and further causes serious damage for the living organism. Thus, accurate quantitative detection of AP sites in mtDNA in a rapid, highly sensitive, and highly selective fashion is important for the real-time evaluation of mtDNA oxidative damage. In this study, a targeting mtDNA ultrasensitive AP site-specific fluorescent rotor (BTBM-CN2) was designed by the strategy of molecular conformation torsion adjustment ratio fluorescent signal. The specific recognition reaction is activated when it encountered AP sites in mtDNA within 20 s, and BTBM-CN2presented a “turn-on” red fluorescence signal at 598 nm. Then, about 100 s later, BTBM-CN2emitted a new green fluorescence signal at 480 nm, which is mainly due to the activation of the rate-limiting reaction. With increasing numbers of AP sites (1–40 in 1 × 105bp of mtDNA), the fluorescence emission at 598 nm decreased gradually, and the new emission at 480 nm increased. Intracellular experiments indicated that BTBM-CN2could detect AP sites in mtDNA in a rapid and quantitative fashion with high selectivity and ultrasensitivity. On the basis of the emergence of the fluorescence signal at 480 nm and its signal strength, the cell whose mtDNA was damaged could be screened by flow cytometry and its degree of damage could be evaluated in real time by comet assay. Hence, the rotor may have potential applications varying from accurate and ultrasensitive detection of AP sites to the real-time evaluation of the oxidative damage in living cells.

Ion pair speciation of ionic liquids (ILs) has an important effect on the physical and chemical properties of ILs and recognition of the structure of ion pairs in solution is essential. It has been reported that ion pairs of some ILs can be formed by hydrogen bonding interactions between cations and anions of them. Considering the fact that far-IR (FIR) spectroscopy is a powerful tool in indicating the intermolecular and intramolecular hydrogen bonding, in this work, this spectroscopic technique has been combined with molecular dynamic (MD) simulation and nuclear magnetic resonance hydrogen spectroscopy (1H NMR) to investigate ion pairs of aprotic ILs [Bmim][NO3], [BuPy][NO3], [Pyr14][NO3], [PP14][NO3] and [Bu-choline][NO3] in aqueous IL mixtures. The FIR spectra have been assigned with the aid of density functional theory (DFT) calculations, and the results are used to understand the effect of cationic nature on the structure of ion pairs. It is found that contact ion pairs formed in the neat aprotic ILs by hydrogen bonding interactions between cation and anion, were still maintained in aqueous solutions up to high water mole fraction (say 0.80 for [BuPy][NO3]). When water content was increased to a critical mole fraction of water (say 0.83 for [BuPy][NO3]), the contact ion pairs could be transformed into solvent-separated ion pairs due to the formation of the hydrogen bonding between ions and water. With the further dilution of the aqueous ILs solution, the solvent-separated ion pairs was finally turned into free cations and free anions (fully hydrated cations or anions). The concentrations of the ILs at which the contact ion pairs were transformed into solvent-separated ion pairs and solvent-separated ion pairs were transformed into free ions (fully hydrated ion) were dependent on the cationic structures. These information provides direct spectral evidence for ion pair structures of the aprotic ILs in aqueous solution. MD simulation and 1H NMR results support the conclusion drawn from FIR spectra investigations.

Abstract Densities for monosaccharide (D-xylose, D-arabinose, D-glucose, D-galactose)–NaI–water solutions were measured at 298.15 K and were used to calculate the apparent molar volumes of these saccharides and NaI. Infinite dilution apparent molar volumes for the saccharides (VF,S°) in aqueous NaI and those for NaI (VF,E°) in aqueous saccharide solutions and partial molar volumes of the saccharides (VS) and NaI (VE) at each composition have been evaluated, together with the standard transfer volumes of the saccharides (?trVS°) from water to aqueous NaI and those of NaI (?trVE°) from water to aqueous saccharide solutions. It was shown that the ? trVS° and ?trVE° values are positive and increase with increasing co-solute molalities. Volumetric parameters indicating the interactions of NaI with saccharides in water were also obtained and applied to explore the interactions between saccharides and NaI in water. A comparison of the ?ES value for NaI with those for NaCl and NaBr showed that for a given saccharide, except for glucose, the ?ES value for NaBr is the largest of three sodium halides (NaCl, NaBr and NaI). These were interpreted in terms of the apparent molar electrostriction volumes (? Ve) and the structure interaction model.

An electromotive force (emf) method was used to determine thermodynamic parameters of interaction of HCl with normal 1-butanol (n-BuOH) in water between 5 and 45°C. A comparison of pair interaction parameters for HCl–n-BuOH with those for HCl–t-BuOH (tert butyl alcohol) showed that there is an obvious difference between them. This was interpreted in terms of steric structure of their carbon chains. The group Gibbs free energy parameters ( $$G_{HCl} - {CH}_{2} $$ and $$G_{HCl} - {OH} $$ ) for the HCl–alcohol–water systems were derived according to the Savage–Wood group additivity principle. These group parameters can be used to evaluate pair interaction parameters of HCl with alcohol molecules.

AbstractThe infrared (IR) and Raman spectra of propylene carbonate (PC) containing various concentrations of LiClO4have been measured and analyzed. The difference in spectra of PC with and without LiClO4was attributed to the interaction of the PC molecules and lithium ions. This interaction occurs mainly on the carbonyl oxygen atom of the PC molecule. The ring deformation, symmetric ring deformation, carbonyl stretching and stretching of ring oxygens for PC are sensitive to this interaction. The solvation number of Li+is also calculated. On the other hand, the structure of the ClO−4is also affected by PC molecule, forming the solvent separated ion pairs.