Harnessing Bottom‐Up Self‐Assembly To Position Five Distinct Components in an Ordered Porous Framework

Abstract

Positioning adiverse set of building blocks in awelldefined arraye nables cooperativity amongst them and the systematic programming of functional properties.T he extension of this concept to porous metal-organic frameworks (MOFs) is challenging since the installation of multiple components in aw ell-ordered framework requires careful design of the lattice topology,j udicious selection of building blocks,a nd precise control of the crystallization parameters. Herein, we report how we met these challenges to prepare the first quinary MOF structure,F DM-8, by bottom-up selfassembly from two metals,Z n II and Cu I ,a nd three distinct carboxylate-and pyrazolate-based linkers.Withasurface area of 3643 m 2 g À1 ,F DM-8 contains hierarchical pores and shows outstanding methane-storage capacity at high pressure.F urthermore,functional groups introduced on the linkers became compartmentalized in predetermined arrays in the pores of the FDM-8 framework.One distinction between synthetic materials and their natural counterparts is their level of structural complexity. Synthetic materials are typically constructed from asmall set of structural units,which places an inherent limitation on their composition and architecture.T he contrast with biological materials,such as DNAand proteins,which are composed of multiple building blocks,isstartling. Owing to acombination of structural complexity and order,s uch biomolecules are capable of sophisticated functions.W hereas conventional synthetic materials lack complexity,t he functionality of biomaterials has inspired attempts to synthesize architectures that position ab road set of building blocks in aw ell-defined array.One prominent example is the design and realization of multicomponent metal-organic frameworks (MOFs). [1] The assembly of these materials relies on the combination of multiple metal clusters and organic linkers.T hese building blocks are distinguished from one another by their coordination preferences (metals) or symmetries and metric parameters (linkers). In this way,they can be positioned in specific positions in the growing lattice,w hich mitigates against randomness and disorder. By drawing on the isoreticular principle, [2] functional groups can be placed on the organic linkers that do not interfere with framework assembly. Accordingly,specific functional groups in proximity generate precisely controlled pore environments.P ores that are programmed in this way lead to designer functions,including enhanced gas storage [3] and cooperative catalysis. [4] Theg eneration of single crystals with multiple components directly from solution becomes increasingly difficult as the number of building blocks is increased because the selfassembly process requires ac ollection of simultaneous interactions to be manipulated in ac ooperative manner.I n the case of MOFs,t he formation of alternative products is fatal, since the purification of crystalline products is virtually impossible.Todate,the number of discrete molecules that can be cocrystallized to occupy inequivalent p...

Reticular Chemistry 3.2: Typical Minimal Edge-Transitive Derived and Related Nets for the Design and Synthesis of Metal–Organic Frameworks

“…Multivariate MOFs with certain complexities can be controlled during the framework assembly process. [179][180][181][182] The mixed linker MOFs can even be designed and synthesized via merged nets approach, a new strategy added to the repertoire of reticular chemistry for the design and construction of intricate mixed-ligands MOFs strategy. 12 To further demonstrate the feasibility of the minimal edge-transitive derived and related nets for the design and synthesis of MOFs, we here selected four minimal edgetransitive nets (i.e.…”

Pseudo-5-Fold-Symmetrical Ligand Drives Geometric Frustration in Porous Metal–Organic and Hydrogen-Bonded Frameworks

“…Reticular framework materials are a class of materials that are constructed by the selection or design of building blocks and linkage groups such that a desired net is formed . This approach is successfully applied for introduction of functionality on the organic linkers and on known metal-based secondary building units (SBU), while structural complexity can be increased by the rational construction of new organic nodes and new nets or by the synthesis of controlled multivariate materials. − Recently, design strategies have emerged that seek to deviate from this approach and attempt to increase complexity by introducing well-defined defects and mismatches into the backbone that lead to reduced symmetry, new nets, and open metal sites . This can be achieved by linker clip-off, dissolution and introduction of defects, − or installation of size- and shape-mismatched linkers .…”

Synthesis of an Interrupted AST‐Type Zeolitic Imidazolate Framework

“…As the subclass of metal‐organic frameworks (MOFs), zeolitic imdazolate frameworks (ZIFs) with high surface area and exceptional stability have exhibited widely potential applications in gas storage, separation, catalysis, electrocatalysis, and so on . In their structures, metal ions ( e.g ., Zn 2+ , Co 2+ , Cd 2+ , etc .)…”