Rising Up: Hierarchical Metal–Organic Frameworks in Experiments and Simulations

Abstract

Controlled synthesis across several length scales, ranging from discrete molecular building blocks to size-and morphology-controlled nanoparticles to 2D sheets and thin films and finally to 3D architectures, is an advanced and highly active research field within both the metal-organic framework (MOF) domain and the overall material science community. Along with synthetic progress, theoretical simulations of MOF structures and properties have shown tremendous progress in both accuracy and system size. Further advancements in the field of hierarchically structured MOF materials will allow the optimization of their performance; however, this optimization requires a deep understanding of the different synthesis and processing techniques and an enhanced implementation of material modeling. Such modeling approaches will allow us to select and synthesize the highest-performing structures in a targeted rational manner. Here, recent progress in the synthesis of hierarchically structured MOFs and multiscale modeling and associated simulation techniques is presented, along with a brief overview of the challenges and future perspectives associated with a simulation-based approach toward the development of advanced hierarchically structured MOF materials. Hierarchical Architecturesand signal transduction. These molecular components are then organized into subcellular and cellular compartments or domains. These subcellular and cellular compartments are then structured into different organs and organ systems, which ultimately, at the highest level, constitute the entire organism. These organisms are then able to self-replicate and are themselves part of more complex ecosystems.Hierarchically organized synthetic materials also contain structural elements at more than one length scale. This structural hierarchy can strongly influence bulk material properties. Understanding the effects of hierarchical structure is essential for guiding the synthesis of new materials with properties that are tailored to specific applications. [2] The individual building blocks in a material, which are often grouped into different subdomains and domains, are usually regarded as structural elements in hierarchical materials. However, other features of materials, such as porosity or chemical composition, can also be organized hierarchically, which is crucial for optimizing specific properties, such as diffusion within a material or directional energy transfer. [3] The hierarchical order of a material may be defined as the number (n) of levels of scale within a specific structure. [2] As in natural systems, such as proteins, one can categorize structures at different length scales starting from the smallest length scale as primary structures, secondary structures, tertiary structures, and so on. [4] Metal-organic frameworks (MOFs) are a class of functional crystalline materials that has received increasing attention over the

Seed-mediated evolution of hierarchical metal–organic framework quaternary superstructures

“…[3][4][5][6] The placement of functionalities that can complete tandem chemical processes would allow for intrinsic tunability over pore environments in hierarchical MOF systems with heterocompositions. [7][8][9][10] Therefore, MOF architectures with well-dened modules and sequences provide great opportunities in extensive elds such as drug delivery, catalysis and sensing. [11][12][13] Seed-mediated growth is considered a viable pathway for fabricating sophisticated architectures.…”

“…The hierarchical order of a MOF superstructure can be regarded as the number n, which is the level of scale within a specic structure (Scheme 1). 7 Similar to proteins which contain primary, secondary, tertiary and quaternary structures, the hierarchy of MOF superstructures includes primary architectures (MOF unit cells) constructed from basic building blocks, secondary architectures such as MOF crystallites, tertiary architectures such as hierarchical assemblies of MOF crystallites, and more complicated quaternary architectures. By utilizing MOF-74-III spherulites as seeds, multiple quaternary architectures with superior hierarchy were obtained (Fig.…”

Advanced technologies for the fabrication of MOF thin films

“…organic linkers, make them multifunctional platforms with tailorable capabilities. [7][8][9] MOFs are conventionally obtained as polycrystalline micro-powders with very low processability. However, their integration onto surfaces and devices is highly desired for a large variety of applications, e.g.…”

Recent developments in the control of selectivity in hydrogenation reactions by confined metal functionalities

“…Metal organic frameworks (MOFs) are well-ordered structures composed of metal ions or clusters connected to each other by coordinating organic linkers. 64 Research on MOFs is a highly active field with currently over 70 000 reported MOF crystal structures, owing to the large number of available metals and organic linkers. 64 However, research on MOFbased catalysts is primarily aimed towards the synthesis of fine chemicals, while few MOFs are being developed for use in the synthesis of commodity chemicals.…”