Covalent Organic Framework Nanohydrogels.

Nanohydrogelation of covalent organic frameworks (COFs) will undoubtedly open up new applications for them in water, such as aqueous catalysis and biomedicine. It is currently a great challenge to achieve water dispersion of COFs through either bottom-up construction strategies or top-down exfoliating technologies. Herein, poly(N-isopropylacrylamide) (PNIPAM)-postmodified COF nanohydrogels (COF-NHGs) are successfully designed and synthesized via in situ atom-transfer radical polymerization (ATRP) on a scaffold of COFs. During the polymer growth process, the bulk COFs are exfoliated into nanosheets with a lateral size of ∼500 nm and a thickness of ∼6.5 nm. Moreover, their size can be precisely controlled by the degree of polymerization of PNIPAMs. In aqueous solution, the obtained COF-NHGs are assembled into nanohydrogels retaining intra-plane crystallinity and exhibit a temperature-sensitive sol-gel phase transition. With excellent solubility in organic solvents, the COF-NHGs' intrinsic physical properties in the solution state can be characterized through their solution nuclear magnetic resonance and ultraviolet absorption spectra. These results put forward new opportunities for regulating the solution processability of COFs and building an intelligent, stimuli-response platform of COF-polymer composite nanohydrogels for device applications.

Triptycene-based Chiral Porous Polyimides for Enantioselective Membrane Separation.

Enantiomers of 2, 6-diaminotriptycene (R, R-1 and S, S-1) are split by chiral-phase HPLC and their absolute configurations are identified by single-crystal X-ray diffraction technology. Using the enantiomers as monomers, a couple of chiral porous polyimides (R-FTPI and S-FTPI) are prepared by polycondensation reactions and display good heat stability, high BET surface area and good solubility in organic solvents. Moreover, both of R-FTPI and S-FTPI can be cast into robust, free-standing films suitable for enantioselective separation with symmetrical chiral selectivity.

Self-similar chiral organic molecular cages.

The endeavor to enhance utility of organic molecular cages involves the evolution of them into higher-level chiral superstructures with self-similar, presenting a meaningful yet challenging. In this work, 2D tri-bladed propeller-shaped triphenylbenzene serves as building blocks to synthesize a racemic 3D tri-bladed propeller-shaped helical molecular cage. This cage, in turn, acts as a building block for a pair of higher-level 3D tri-bladed chiral helical molecular cages, featuring multilayer sandwich structures and displaying elegant characteristics with self-similarity in discrete superstructures at different levels. The evolutionary procession of higher-level cages reveals intramolecular self-shielding effects and exclusive chiral narcissistic self-sorting behaviors. Enantiomers higher-level cages can be interconverted by introducing an excess of corresponding chiral cyclohexanediamine. In the solid state, higher-level cages self-assemble into supramolecular architectures of L-helical or D-helical nanofibers, achieving the scale transformation of chiral characteristics from chiral atoms to microscopic and then to mesoscopic levels.

Thermo-controlled Water Microenvironment Inducing Fluorescence Enhancement of Chalcone Nanohydrogels for Mitochondrial Temperature Sensing.

Developing aggregation-induced emission (AIE)-based hydrogels that exhibit fluorescence enhancement as to thermal properties is an interesting and challenging task. In this work, we employed the fluorophore 2'-hydroxychalcone (HC), fluorescence properties of which are easily influenced by the excited-state intramolecular proton transfer and twisted intramolecular charge transfer (TICT) effects, to develop a novel type of temperature-sensitive polymers, hydroxychalcone-based polymers (HCPs). By controlling the temperature-dependent water microenvironments in HCPs, the intramolecular hydrogen bonds between water and HCPs can be regulated, thereby influencing the TICT process and leading to thermo-induced fluorescence enhancement, which shows a contrary tendency compared to typical AIEgens that always exhibit fluorescence attenuation as the thermal energy accelerates the molecular motion. Following the decoration with triphenylphosphine, the resulting polymer P-HCP assembled into nanohydrogels and served as a fluorescent probe for intracellular mitochondrial temperature sensing.

Porous Triptycene Network Based on Tröger's Base for CO2 Capture and Iodine Enrichment.

A three-dimensional rigid "six-connected" porous triptycene network based on Tröger's base (TB-PTN) was synthesized by using triptycenes as connectors and Tröger's base as linkers. With characteristics of a high surface area of 1528 m2 g-1, nitrogen-enriched groups, and superior thermal stability, TB-PTN displays a high CO2 uptake of 22.3 wt % (273 K, 1 bar) and excellent iodine vapor adsorption (240 wt %).

Chiral emissive porous organic cages.

A pair of chiral, emissive and porous tubular multi-functional organic molecular cages were synthesized easily by imine chemistry of 4,4',4'',4'''-(ethene-1,1,2,2-tetrayl)-tetrabenzaldehyde (ETTBA) with (R,R)- or (S,S)-diaminocyclohexane (CHDA). It was found that the chirality of CHDA was transferred and amplified to tetraphenylethylene (TPE) in the process of formation of cages, which further endowed the cages with circularly polarized luminescence (CPL) characteristics. As a result of the synergy of the chirality and porous structure in the solid state, both cages exhibited a good chiral adsorption enantioselectivity to a series of aromatic racemates.

Highly covalent molecular cage based porous organic polymer: pore size control and pore property enhancement.

It remains a great challenge to effectively control the pore size in porous organic polymers (POPs) because of the disordered linking modes. Herein, we used organic molecular cages (OMCs), possessing the properties of fixed intrinsic cavities, high numbers of reactive sites and dissolvable processability, as building blocks to construct a molecular cage-based POP (TPP-pOMC) with high valency through covalent cross coupling reaction. In the formed TPP-pOMC, the originating blocking pore channels of TPP-OMC were "turned on" and formed fixed pore channels (5.3 Å) corresponding to the connective intrinsic cavities of cages, and intermolecular pore channels (1.34 and 2.72 nm) between cages. Therefore, TPP-pOMC showed significant enhancement in Brunauer-Emmett-Teller (BET) surface area and CO2 adsorption capacity.

Emissive oxidase-like nanozyme based on an organic molecular cage.

In this study, we introduced four "claw-like" units of dipicolylamine (DPA) to a tetraphenylethylene (TPE)-based organic molecular cage (DPA-TPE-Cage). Coordinated with Zn2+ ions, the obtained ZnDPA-TPE-Cage exhibited aggregation induced emission (AIE) effects and oxidase-like properties, which endowed it with the ability to selectively image and kill Gram-positive bacteria S. aureus efficiently.

Efficient alkaloid capture from water using a charged porous organic polymer.

Berberine hydrochloride (BH), an important alkaloid, can be captured from water and released in organic solution circularly by a charged porous polymer (TPB-HCP), which is hypercross-linked using the cost-effective Friedel-Crafts reaction using sodium tetraphenylborate as the monomer. With high BET surface area, hierarchical porous structure and charged characteristics, TPB-HCP displays excellent adsorption capacity for BH owing to the synergistic effects of size matching and electrostatic interaction.

Networked Cages for Enhanced CO2 Capture and Sensing.

It remains a great challenge to design and synthesize a porous material for CO2 capture and sensing simultaneously. Herein, strategy of "cage to frameworks" is demonstrated to synthesize fluorescent porous organic polymer (pTOC) by using tetraphenylethylene-based oxacalixarene cage (TOC) as the monomer. The networked cages (pTOC) have improved porous properties, including Brunauer-Emmett-Teller surface area and CO2 capture compared with its monomer TOC, because the polymerization overcomes the window-to-arene packing modes of cages and turns on their pores. Moreover, pTOC displays prominent reversible fluorescence enhancement in the presence of CO2 in different dispersion systems and fluorescence recovery for CO2 release in the presence of NH3·H2O, and is thus very effective to detect and quantify the fractions of CO2 in a gaseous mixtures.

Single-nucleotide polymorphism-gene intermixed networking reveals co-linkers connected to multiple gene expression phenotypes.

Gene expression profiles and single-nucleotide polymorphism (SNP) profiles are modern data for genetic analysis. It is possible to use the two types of information to analyze the relationships among genes by some genetical genomics approaches. In this study, gene expression profiles were used as expression traits. And relationships among the genes, which were co-linked to a common SNP(s), were identified by integrating the two types of information. Further research on the co-expressions among the co-linked genes was carried out after the gene-SNP relationships were established using the Haseman-Elston sib-pair regression. The results showed that the co-expressions among the co-linked genes were significantly higher if the number of connections between the genes and a SNP(s) was more than six. Then, the genes were interconnected via one or more SNP co-linkers to construct a gene-SNP intermixed network. The genes sharing more SNPs tended to have a stronger correlation. Finally, a gene-gene network was constructed with their intensities of relationships (the number of SNP co-linkers shared) as the weights for the edges.