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Novel deep eutectic solvents (DES) based on three different hydrogen-bond donors (HBD), namely phenol, o-cresol, and 2,3-xylenol, and choline chloride (ChCl) were successfully synthesized with different mole ratios of HBD to ChCl. Melting temperature of these DES were measured. Compared with an ideal mixture of the two components, the freezing temperature of the DES depresses greatly from (120 to 127) K. The physical properties, such as density, viscosity, and conductivity of phenol-based and o-cresol-based DES were determined at atmospheric pressure and temperatures from (293.2 to 318.2) K at an interval of 5 K. The results show that the type of HBD, the mole ratio of HBD to ChCl, and temperature have great influences on the physical properties of DES. Densities and viscosities of DES formed by phenol and ChCl decrease with increases of temperature and phenol content. The conductivities of the DES are from (1.40 to 7.06) mS·cm–1, similar to that of room temperature ionic liquids. The conductivities of the DES increase with an increase of temperature, and reach the highest values at phenol to ChCl mole ratios of 4.00 to 5.00. The temperature dependence of densities and conductivities for these DES were correlated by an empirical second-order polynomial with relative deviations less than 0.91 %, and the viscosities were fitted to the VTF equation with relative deviations less than 0.52 %.

Ammonium salts have been used to efficiently separate phenols from oils (where hexane, toluene and p-xylene were used as model oils) by forming a deep eutectic solvent, which is a nonaqueous process and avoids the use of mineral alkalis and acids that produces phenol containing waste water.

Pure organic room temperature phosphorescence (RTP) is highly preferable because of its long lifetime and potential applications. However, these kinds of materials are still very scarce due to the weak spin-orbit coupling between singlet and triplet states and easily nonradiative decay of the excited states. Achieving room temperature phosphorescence under visible light excitation is particularly challenging in aqueous solution. Herein, a micelle-assisted assembling strategy has been developed to realize pure organic RTP in water by using donor-acceptor molecules. A visible-light responsive long-lived RTP in water with a lifetime more than 3 ms is obtained by the prepared nanocrystals. However, the same molecules show no RTP as rigid bulk crystals. Spectroscopic studies, single-crystal structure analysis, X-ray diffraction patterns, and density functional theory calculations reveal that the intermolecular interactions, heavy atom effect, and the molecular packing way play critical role to the long-lived RTP character for the assembled nanocrystals in water and thermally activated delayed fluorescence for crystals in solid.

Supramolecular architectures are constructed by the self‐assembly of small building blocks via the use of metal‐ligand coordination, π–π stacking interactions, hydrogen bonding, host‐guest interactions, and other noncovalent driving forces, which confer unique dynamic reversibility and stimulus responsiveness to the supramolecular materials and also lead to the demand of expensive and complex equipment for the characterization of supramolecular assembly processes. Fortunately, the self‐assembly processes bring the monomeric chromophores together, offering possibilities to establish ties between the supramolecular assembly and aggregation‐induced emission (AIE) techniques. Compared to conventional luminescent molecules, AIE luminogens (AIEgens) exhibit significant fluorescence enhancement upon the restriction of molecular motions, thus displaying the advantages of signal amplification and low background noises. Given the above, the real‐time, sensitive, and in situ visualization of the formation of self‐assemblies and their stimuli responsiveness based on AIE becomes accessible. Here, we review recent works that encompass the visualization of supramolecular assembly‐related behaviors by means of AIE characteristics of chromophores. The organization of this review will be by different types of supramolecular architectures, including metallacycles/cages, micelles/vesicles, supramolecular polymers, and supramolecular gels. An overview of future opportunities and challenges for the real‐time monitoring of supramolecular assembly by AIE is also provided.

Fungal infection poses and increased risk to human health. Photodynamic therapy (PDT) as an alternative antifungal approach garners much interest due to its minimal side effects and negligible antifungal drug resistance. Herein, we develop stereoisomeric photosensitizers ((Z)- and (E)-TPE-EPy) by harnessing different spatial configurations of one molecule. They possess aggregation-induced emission characteristics and ROS, viz. 1O2 and O2−• generation capabilities that enable image-guided PDT. Also, the cationization of the photosensitizers realizes the targeting of fungal mitochondria for antifungal PDT killing. Particularly, stereoisomeric engineering assisted by supramolecular assembly leads to enhanced fluorescence intensity and ROS generation efficiency of the stereoisomers due to the excited state energy flow from nonradiative decay to the fluorescence pathway and intersystem (ISC) process. As a result, the supramolecular assemblies based on (Z)- and (E)-TPE-EPy show dramatically lowered dark toxicity without sacrificing their significant phototoxicity in the photodynamic antifungal experiments. This study is a demonstration of stereoisomeric engineering of aggregation-induced emission photosensitizers based on (Z)- and (E)-configurations.

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Organic room temperature phosphorescence (RTP) in water has attracted much attention recently for its potential biological applications. However, it remains a formidable challenge to achieve efficient RTP from pure organic compounds in aqueous phase due to the dramatic deactivation of triplet excited states in water and the poor water dispersibility of large organic particles/crystals. Represented herein is covalent incorporation of a pure organic monochromophore in silica nanoparticles (SiNPs) featuring fluorescence and bright phosphorescence in aqueous solution. The covalent bonding of organic phosphors in polysiloxane framework was found to show excellent water dispersibility, at the same time suppress the non‐radiative deactivation of triplet excited states especially from water, thus leading to high phosphorescence quantum yields (up to 22%) and long lifetimes (up to 3.5 ms) in aqueous phase. More strikingly, oxygen‐insensitive fluorescence as internal reference and oxygen‐dependent phosphorescence as oxygen indicator from the organic chromophore in the porous SiNPs realized ratiometric hypoxia detection with ultrasensitivity (KSV = 449.3 bar−1).