Three-dimensional covalent organic frameworks (3D COFs) are promising crystalline materials with well-defined structures, high porosity, and low density; however, the limited choice of building blocks and synthetic difficulties have hampered their development. Herein, we used a flexible and aliphatic macrocycle, namely γ-cyclodextrin (γ-CD), as the soft struts for the construction of a polymeric and periodic 3D extended network, with the units joined via tetrakis(spiroborate) tetrahedra with various counterions. The inclusion of pliable moieties in the robust open framework endows these CD-COFs with dynamic features, leading to a prominent Li ion conductivity of up to 2.7 mS cm at 30 °C and excellent long-term Li ion stripping/plating stability. Exchanging the counterions within the pores can effectively modulate the interactions between the CD-COF and CO molecules.

Activation of photosensitizers (PSs) in targeted lesion and minimization of reactive oxygen species (ROS) depletion by endogenous antioxidants constitute promising approaches to perform highly effective image-guided photodynamic therapy (PDT) with minimal non-specific phototoxicity. Traditional strategies to fabricate controllable PS platforms rely on molecular design, which requires specific modification of each PS before PDT. Therefore, construction of a general tumor-responsive PDT platform with minimum ROS loss from endogenous antioxidant, typically glutathione (GSH), is highly desirable. Herein, MOF-199, a Cu(II) carboxylate-based metal−organic framework (MOF), is selected to serve as an inert carrier to load PSs with prohibited photosensitization during delivery. After cellular uptake, Cu (II) in the MOFs effectively scavenges endogenous GSH, concomitantly induces decomposition of MOF-199 to release the encapsulated PSs, and recovers their ROS generation. In vitro and in vivo experiments demonstrate highly effective cancer cell ablation and anticancer PDT with diminished normal cell phototoxicity. This strategy is generally applicable to PSs with both aggregation-induced emission and aggregation-caused quenching to implement activatable and enhanced image-guided PDT.

Metal-organic frameworks (MOFs) with high porosity and designable functionality make it possible to access the merits of high permeability and selectivity. However, scalable fabrication methods to produce mixed matrix membranes (MMMs) with good flexibility and ultrahigh MOF loading are urgently needed yet largely unmet. Herein, we report a thermally induced phase separation-hot pressing (TIPS-HoP) strategy to roll-to-roll produce 10 distinct MOF-membranes (loadings up to 86 wt%). Ultrahigh-molecular-weight polyethylene interweaving the MOF particles contributes to their mechanical strength. Rejections (99%) of organic dyes with a water flux of 125.7 L m–2 h–1 bar–1 under cross-flow filtration mode. The micron-sized channels between the MOF particles translate into fast water permeation, while the porous MOFs reject solutes through rapid adsorption. This strategy paves ways for developing high-performance membrane adsorbers for crucial separation processes. As a proof-of-concept, the abilities of the membrane adsorbers for separating racemates and proteins have been demonstrated.

Three-dimensional covalent organic frameworks (3D COFs) are promising crystalline materials with welldefined structures,high porosity,and low density;however,the limited choice of building blocks and synthetic difficulties have hampered their development. Herein, we used af lexible and aliphatic macrocycle,n amely g-cyclodextrin (g-CD), as the soft struts for the construction of apolymeric and periodic 3D extended network, with the units joined via tetrakis(spiroborate) tetrahedra with various counterions.T he inclusion of pliable moieties in the robust open framework endows these CD-COFs with dynamic features,l eading to ap rominent Li ion conductivity of up to 2.7 mS cm À1 at 30 8 8Ca nd excellent long-term Li ion stripping/plating stability.E xchanging the counterions within the pores can effectively modulate the interactions between the CD-COF and CO 2 molecules.Covalent organic frameworks (COFs) are porous crystalline polymers constructed from purely organic building blocks, and feature large surface areas,w ell-defined structures, tunable functionalities,low densities,aswell as good thermal stabilities. [1] These intriguing advantages render COFs ideal candidates for applications in gas storage and separation, [2] optoelectronics, [3] catalysis, [4] and energy storage, [5] forexample.W hen classified according to their structural dimensions, COFs can be divided into two-dimensional (2D) and threedimensional (3D) frameworks.I n2 DC OFs,t he building blocks are periodically and covalently restrained in 2D polymeric layers,w hich can further stack to form eclipsed or staggered structures through non-covalent interactions. [6] In 3D COFs,t he structural units are chemically and geometrically extended into three-dimensional space via tetrahedral linkages.Unlike the rapid expansion of 2D COFs,the progress in 3D COF chemistry has been severely impeded by the limited choice of monomers and synthetic difficulties.The molecular building units that have been reported for 3D COF synthesis to date are all aromatic compounds as their rigid structures possess discrete directionality that favors the periodic spatial arrangement and extension of the framework. In all of the known 3D COFs, [4c, 7] the tetrahedral linkages are based on either sp 3 -hybrized carbon or silane elements.T he development of 3D COFs that are based on soft and flexible building units,such as cyclodextrins (CDs), which may impart the COFs with dynamic and resilient characteristics,ishighly desired, yet largely unmet.Appropriate organic reactions that allow for "errorchecking" and "proof-reading" will play av ital role in geometrically positioning and covalently linking CD in certain orientations to form 3D CD-COFs and provide channels with dynamic functional groups.T he CD building units are cyclic oligosaccharides,w ith ac avity for guest inclusion and ar ing structure of glucopyranose units that is rich in primary and secondary OH groups. [8] These hydroxy groups can serve as chelating and nucleophilic sites and provide the opportunity to link C...

Metal–organic frameworks (MOFs) with long‐term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT‐66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT‐66 (V3(O)3(H2O)(BTB)2), possesses prominent moisture tunability in the range of 45–60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption–desorption cycles. Importantly, this MOF demonstrates a unique photocatalytic bacteriostatic behavior under visible light, which can effectively ameliorate the bacteria and/or mold breeding problem in water adsorbing materials.

No abstract

Phosphorescent 2D covalent organic frameworks were utilized as a research platform to study the relationship between phosphorescence emission and interlayer distance.

Tumor accumulation and intratumoral singlet oxygen (1O2) generation efficiency of photosensitizers (PSs) are two essential factors that determine their photodynamic therapy (PDT) efficacies. How to maximize the PS performance at the tumor site is of great research interest. Herein, we report a metal–organic framework (ZIF-8, ZIF = zeolitic imidazolate framework) assisted in vivo self-assembly nanoplatform, ZIF-8-PMMA-S-S-mPEG, as an effective tool for organic PS payloads to achieve efficient PDT. Using an organic PS with aggregation-induced emission as an example, under intratumoral bioreduction, PS-loaded ZIF-8-PMMA-S-S-mPEG (PS@ZIF-8-PMMA-S-S-mPEG) was self-assembled into large ordered hydrophobic clusters, which greatly enhance tumor retention and accumulation of the PS. Moreover, hydrophobic ZIF-8 assemblies greatly isolate the loaded PSs from water and improve O2 transport for the PSs to effectively produce 1O2 inside tumors under light irradiation. The organic PS is therefore endowed with optimal tumor accumulation and intratumoral 1O2 production, demonstrating the effectiveness of the developed self-assembly strategy in PDT application.