Vicinal dual hydroxyl functional mesoporous poly(ionic liquid)s with large surface area and high ionic liquid (IL) content were synthesized through the copolymerization of epoxy-containing IL monomers and divinylbenzene, followed by ring opening in water. They acted as recyclable heterogeneous organocatalysts in the cycloaddition of a series of epoxides with CO 2 under mild conditions (down to ambient conditions). The catalyst can be lightly recovered and reused with stable activity. The remarkable performance was attributable to the abundant mesoporosity and the synergistic effect of vicinal dual hydroxyls as hydrogen-bonding donors and halogen anions as nucleophiles. Density functional theory calculation, comprising the structural optimization, the energetic profile, and the charge and energy decomposition analysis by the combination of the extended transition state energy decomposition scheme with the natural orbitals for chemical valence approach, was performed to afford insight, indicating that the vicinal dual hydroxyls accelerated the reaction by providing a strong hydrogen-bonding effect and enhancing the leaving ability of the halogen anions.

Near-infrared (NIR) light can penetrate biological samples and even tissues without causing sample damage and avoid autofluorescence from biological samples in fluorescence detection. Thus, a luminescence resonance energy transfer (LRET)-based immunoassay that can be excited by NIR irradiation is a promising approach to the analysis of biological samples. Here we demonstrate the use of NIR-to-visible upconversion nanoparticles (UCNPs) as an energy donor, which can emit a visible light upon the NIR irradiation, and gold nanoparticles (Au NPs) as an energy acceptor, which can absorb the visible light emitted from the donor, to develop a sandwich-type LRET-based immunoassay for the detection of goat antihuman immunoglobulin G (IgG). Amino-functionalized NaYF(4):Yb, Er UCNPs and Au NPs were first prepared and then conjugated with the human IgG and rabbit antigoat IgG, respectively. The NIR-excited fluorescence emission band of human IgG-conjugated NaYF(4):Yb, Er UCNPs (lambda(max) = 542 nm) partially overlaps with the visible absorption band of the rabbit antigoat IgG-conjugated colloidal Au NPs (lambda(max) = 530 nm), satisfying the requirement of spectral overlap between donors and acceptors for LRET. A LRET system was then formed when goat antihuman IgG was added to a mixture of human IgG-modified NaYF(4):Yb, Er UCNPs (donor) and rabbit antigoat IgG-modified Au NPs (acceptor). The sandwich-type immunoreactions between the added goat antihuman IgG (primary antibody) and the two different proteins (antigen and secondary antibody on the surface of the donors and acceptors, respectively) cross-bridge the donors and acceptors and thus shorten their spacing, leading to the occurrence of LRET from UCNPs to Au NPs upon NIR irradiation. As a result, the quenching of the NIR-excited fluorescence of the UCNPs is linearly correlated to the concentration of the goat antihuman IgG (in the range of 3-67 microg x mL(-1)) present in the system, enabling the detection and quantification of the antibody. Such sandwich-type LRET-based approach can reach a very low detection limit of goat antihuman IgG (0.88 microg x mL(-1)), indicating that this method is applicable for the trace protein detection. This approach is expected to be extended to the detection of other biological molecules once the donor and acceptor nanoparticles are modified by proper molecules that can recognize the target biomolecules.

luminogens with aggregation-induced emission (AIE) properties, referred to as AIEgens, first discovered by Tang and coworkers in 2001, exhibit enhanced emission in the aggregated state, [1] leading to the rapid development of AIE materials with diverse applications in ion detection, [2] explosive sensors, [3] cell imaging, [4] photodynamic therapy, [5] optoelectronic systems, [6] and light-harvesting systems. [7] A seminal approach to fabricate smart luminescent materials is the manipulation of AIEgens with supramolecular macrocycle-based host-guest chemistry, which could induce remarkable enhancement of fluorescence intensity of materials due to the host-guest interactions between macrocycles and AIEgens that restrict the intramolecular rotation of luminophores.[8] Pillar[n]arenes, as a new generation of synthetic macrocyclic hosts first reported by Ogoshi et al. in 2008, have proved captivating advantages including symmetrical and rigid structure, versatile functionality, [9] and good solubility. [10] Among the members of the pillar[n]arene family, pillar[5]arene and its derivatives, in which 1,4-disubstituted hydroquinones are connected by five methylene units in the 2,5-positions, exhibit the advantages of: 1) desirable host candidate to bind neutral molecules in organic solvents due to the electron-rich cavity; [11] 2) high yielding in the preparation process for further functionalization; [12] and 3) rigid structure donated stiff component in the fabrication of functional materials, and have showed great potential in sensors, [13] biomedical field, [14] catalysts, [15] separation and storage, [16] supramolecular gels, [17] and light-harvesting systems. [18] For instance, Huang and co-workers constructed an elegant host-guest inclusion complex from water-soluble pillar[6]arene and a tetraphenylethene (TPE) derivative that exhibited strong fluorescence in dilute solution. [19] Interestingly, fluorescent supramolecular assemblies that possess stimuli-responsive properties and dynamic features have been fabricated from AIEgen-containing building blocks, in particular with the aid of supramolecular macrocycles, such as crown ethers, [20] calix[n]arenes, [21] cyclodextrins, [22] cucurbit[n] urils, [23] and pillar[n]arenes, [21,24] instead of simple addition of poor solvents to induce the formation of disorganized aggregates. However, research on the cooperative manipulation of AIE by a polymer host material that contains many synthetic macrocycles installed on one single polymer chain has rarely Linear copolymer hosts bearing a number of pillar[5]arene dangling side chains are synthesized for the facile construction of highly emissive supramolecular polymer networks (SPNs) upon noncovalently cross-linking with a series of tetraphenyethylene (TPE)-based tetratopic guests terminated with different functional groups through supramolecular host-guest interactions. An extremely high fluorescence quantum yield (98.22%) of the SPNs materials is obtained in tetrahydrofuran (THF) by fine-tuning the parameters...

Au–Pd nanoalloy in hydrophilic mesoporous poly(ionic liquid) shows high activity for oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid with atmospheric O2.

Supported catalysts are widely studied, and exploring new promising supports is significant to access more applications. In this work, novel copper-containing MOR-type zeolites Cu-MOR were synthesized in a one-pot template-free route and served as efficient supports for vanadium oxide. In the heterogeneous oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) with molecular oxygen (O2) under ambient pressure, the obtained catalyst demonstrated high yield (91.5%) and good reusability. Even under the ambient air pressure, it gave a DFF yield of 72.1%. Structure-activity relationship analysis indicated that the strong interaction between the framework Cu species and the guest V sites accounted for the remarkable performance. This work reveals that the Cu-MOR zeolite uniquely acts as the robust support toward well-performed non-noble metal heterogeneous catalyst for biomass conversion.

Recent progress in POM-based phase transfer catalysis for liquid–solid organic reactions is summarized in this review.

The task-specific binary catalyst composed of nanobelt α-CuV2O6 and hydrophilic mesoporous poly(ionic liquid) exhibited high efficiency and stable activity in the direct synthesis of 2,5-diformylfuran (DFF) from fructose.

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