Ionic covalent organic frameworks (ICOFs) have recently emerged as promising candidates for solid-state electrolytes. Herein, we report the first example of a series of crystalline imidazolate-containing ICOFs as single-ion conducting COF solid electrolyte materials, where lithium cations freely travel through the intrinsic channels with outstanding ion conductivity (up to 7.2 × 10–3 S cm–1) and impressively low activation energy (as low as 0.10 eV). These properties are attributed to the weak Li ion–imidazolate binding interactions and well-defined porous 2D framework structures of such ICOFs. We also investigated the structure–property relationship by varying the electronic properties of substituents (electron donating/withdrawing) that covalently attached to the imidazolate groups. We found electron-withdrawing substituents significantly improve the ion-conducting ability of imidazolate-ICOF by weakening ion-pair interactions. Our study provides a convenient bottom-up approach toward a novel class of highly efficient single-ion conducting ICOFs which could be used in all solid-state electrolytic devices.

Malleable thermosets are crosslinked polymers containing dynamic covalent bonds, which can be reversibly cleaved and reformed. They have attracted considerable attention in recent years due to their combined advantages of thermosets and thermoplastics. They have excellent mechanical properties and thermal and chemical stabilities like traditional thermosets yet are reprocessable and recyclable like thermoplastics. Although the chemical composition plays an important role in determining the mechanical and thermal properties of materials, the application of dynamic covalent chemistry is the key to achieving the unique properties of malleable thermosets. The mechanism of reversible bond cleavage and reformation, bond activation energies and kinetics, and the conditions triggering such reversibility define the malleable properties of the materials, how and why they can be reprocessed, and when the materials fail. In this review, we introduce fundamental concepts and principles of malleable thermosets, dynamic covalent chemistry, and the characteristic materials properties, including reprocessability, rehealability, and possible recyclability. We categorize the recent literature examples based on the underlying chemistry to demonstrate how dynamic covalent chemistry is exploited in malleable thermosets and how their malleable properties can be achieved and altered; we also discuss intriguing future opportunities based on such exploitation.Highly crosslinked covalent network polymers, commonly called thermosets, generally provide outstanding mechanical properties, chemical and heat resistance, and dimensional stability. Thermosets have found extensive variety of applications ranging from kettle handles and surface coatings to auto bodies. However, since thermosets are cured through the formation of irreversible chemical bonds, 1,2 they cannot be reprocessed or recycled upon failure. 3 Furthermore, any shape change that occurs due to reversible bond-exchange reactions (e.g., disulfide crosslinks) has been known as ''creep'' and has been considered a drawback of polymeric materials. 4 Therefore, it is by design that thermoset networks are irreversible and essentially unrecyclable.Thermoplastics, which consist of linear polymer chains with no crosslinks between them, represent reprocessable and fully recyclable polymeric materials. The thermoprocessing involves weakening of intermolecular forces between polymer chains, and no chemical bonding takes place. As a result, thermoplastics can be reshaped by heating many times without negatively affecting physical properties of the materials. However, they usually exhibit inferior chemical resistance and hightemperature mechanical properties compared with thermosets.Recently, covalent adaptable network (CAN) polymers have been developed, which combine excellent mechanical properties of thermosets with reprocessability of thermoplastics. [5][6][7] This new class of polymer networks incorporates dynamic

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This tutorial review covers the recent design, synthesis, characterization, and property study of COF thin films and covalent monolayers through interfacial polymerization.

All-solid-state lithium ion batteries (LIBs) are ideal for energy storage given their safety and long-term stability. However, there is a limited availability of viable electrode active materials. Herein, we report a truxenone-based covalent organic framework (COF-TRO) as cathode materials for allsolid-state LIBs. The high-density carbonyl groups combined with the ordered crystalline COF structure greatly facilitate lithium ion storage via reversible redox reactions. As a result, a high specific capacity of 268 mAh g À1 , almost 97.5 % of the calculated theoretical capacity was achieved. To the best of our knowledge, this is the highest capacity among all COF-based cathode materials for all-solid-state LIBs reported so far. Moreover, the excellent cycling stability (99.9 % capacity retention after 100 cycles at 0.1 C rate) shown by COF-TRO suggests such truxenone-based COFs have great potential in energy storage applications.

The development of 2D electrically conductive metal− organic frameworks (EC-MOFs) has significantly expanded the scope of MOFs' applications into energy storage, electrocatalysis, and sensors. Despite growing interest in EC-MOFs, they often show low surface area and lack functionality due to the limited ligand motifs available. Herein we present a new EC-MOF using 2,3,8,9,14,15-hexahydroxyltribenzocyclyne (HHTC) linker and Cu nodes, featuring a large surface area. The MOF exhibits an electrical conductivity up to 3.02 × 10 −3 S/ cm and a surface area up to 1196 m 2 /g, unprecedentedly high for 2D EC-MOFs. We also demonstrate the utilization of alkyne functionality in the framework by postsynthetically hosting heterometal ions (e.g., Ni 2+ , Co 2+ ). Additionally, we investigated particle size tunability, facilitating the study of size−property relationships. We believe that these results not only contribute to expanding the library of EC-MOFs but shed light on the new opportunities to explore electronic applications.

Alkyne metathesis represents a rapidly emerging synthetic method that has shown great potential in small molecule and polymer synthesis. However, its practical use has been impeded by the limited availability of user-friendly catalysts and their generally high moisture/air sensitivity. Herein, we report an alkyne metathesis catalyst system that can operate under open-air conditions with a broad substrate scope and excellent yields. These catalysts are composed of simple multidentate tris(2-hydroxyphenyl)methane ligands, which can be easily prepared in multi-gram scale. The catalyst substituted with electron withdrawing cyano groups exhibits the highest activity at room temperature with excellent functional group tolerance (-OH, -CHO, -NO2, pyridyl). More importantly, the catalyst provides excellent yields (typically >90%) in open air, comparable to those operating under argon. When dispersed in paraffin wax, the active catalyst can be stored on a benchtop under ambient conditions without any decrease in activity for one day (retain 88% after 3 days). This work opens many possibilities for developing highly active user-friendly alkyne metathesis catalysts that can function in open air.

The recent synthesis of novel shape-persistent 2D and 3D molecular architectures via alkyne metathesis is reviewed and the critical role of catalysts is also highlighted.