costume designing, penetrates everywhere in our daily lives. As indicated in the definition, the most important two points in the design are understanding "how something will look, work, etc." and being able to "draw plans, make models, etc." For the prior point, it requires in-depth research on the basic subjects related to it, such as physics to architectural design. As for the latter, it requires a lot of practice and experience accumulation. In scientific research, the design of new materials also follows the same rules. At first, the advent of a new material generally comes from occasional discovery. After appropriate understanding of the structure, synthesis method, and mechanism, we can attain a certain degree of design and targeted synthesis. Promptly, with the ongoing maturity of design theory and synthesis methods, further development on the functionalization and applications will come along. From "discovery" to "design" to "development," every leap through the stage has important scientific problems to be solved and, among which, the microfine design is an essential part of any new materials, especially for microporous materials, in the process from design to development. Metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are a new class of crystalline hybrid porous materials encompassing organic linkers and inorganic metal moieties/clusters. [1-9] Due to their excellent structural designability and tunable pore system, they have attracted extensive attention in academia and industry alike and explored in various key applications pertaining to gas storage/separation, [10-16] catalysis, [17-20] luminescence, [21-23] biomedicine, [24-27] proton conduction, [28-30] etc. Different from other traditional porous materials (zeolites, activated carbons, etc.), the inherent diversity of MOFs is more suitable for on-demand targeted design, and the intrinsic hybrid feature comprised of inorganic and organic components enriches the prospect applications of MOFs. The assembly concepts based on novel secondary building units (SBUs) and different topologies enabled MOFs to flourish in the last two decades. Furthermore, the introduction of the molecular building block (MBB) and the supermolecular building block (SBB) approaches have led to the rational design of MOFs, and continuous progress in synthetic methods has also bestowed scientists control over these intricate self-assembly Metal-organic frameworks (MOFs) have emerged as an important and unique class of functional crystalline hybrid porous materials in the past two decades. Due to their modular structures and adjustable pore system, such distinctive materials have exhibited remarkable prospects in key applications pertaining to adsorption such as gas storage, gas and liquid separations, and trace impurity removal. Evidently, gaining a better understanding of the structure-property relationship offers great potential for the enhancement of a given associated MOF property either by structural adjustments via isoreticular chemistry or by the ...

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With the utilization of a "bifunctional liganddirected strategy", three isostructural indium−organic frameworks based on dual secondary building units (SBUs) were successfully constructed with targeted structures. In their frameworks, two types of unsaturated monomeric indium SBUs[In(OOC-) 2 (-N-)X(H 2 O)] and [In(OOC-) 2 (-N-)X 2 ] − (X = Cl, Br, and I)assemble to form 1D tubular channels with both open metal sites and weak base polarizing substituents. The trimeric indium SBUs [In 3 O(OOC-) 6 (DMA) 3 ] + serve as robust external linkers to extend into a 3D honeycomb double-walled framework with nanoscale channels. By changing the polarizing substituents in situ with different halogens (Cl − , Br − , and I − ), three obtained isostructural MOFs show different channel characteristics, such as alkalinity of the polarizing substituents, acidity of the polarized open indium sites, extended channel sizes, and increased pore volumes (from -I to -Cl). Subsequently, we took the three MOFs collectively as a platform to investigate the impact of the different coordinated halide ions on channel functions, especially on CO 2 adsorption and chemical conversion. Accordingly, the three nanochannel MOF catalysts exhibited highly effective performances in catalyzing cycloaddition of CO 2 with large-sized epoxides, particularly styrene oxide, into value-added productsstyrene carbonates with yields of 91−93% and high selectivity of 95−98%under mild conditions. We speculated that the superior catalytic efficiencies of the three MOF catalysts could be ascribed to the synergistic effect of open indium sites as Lewis acid with different halide ions as weak base sites, which might enhance the catalytic selectivity through polarizing and activating CO 2 molecules during the reaction process.