Spatial distribution modulation of mixed building blocks in metal-organic frameworks

Abstract

The placement of mixed building blocks at precise locations in metal–organic frameworks is critical to creating pore environments suitable for advanced applications. Here we show that the spatial distribution of mixed building blocks in metal–organic frameworks can be modulated by exploiting the different temperature sensitivities of the diffusion coefficients and exchange rate constants of the building blocks. By tuning the reaction temperature of the forward linker exchange from one metal–organic framework to another isoreticular metal–organic framework, core–shell microstructural and uniform microstructural metal–organic frameworks are obtained. The strategy can be extended to the fabrication of inverted core–shell microstructures and multi-shell microstructures and applied for the modulation of the spatial distribution of framework metal ions during the post-synthetic metal exchange process of a Zn-based metal–organic framework to an isostructural Ni-based metal–organic framework.

Defined metal atom aggregates precisely incorporated into metal–organic frameworks

“…178 ICP-OES is typically used for the analysis of the purity of the MOF material and for the quantification of elemental ratios. 179,180 (ii) MA characterisation. With the analytical focus on the MA species essential information must be collected about loading, size (distribution) and oxidation state(s) as well as location, distribution (cf.…”

“…178 ICP-OES is typically used for the analysis of the purity of the MOF material and for the quantification of elemental ratios. 179,180…”

Macroscopic alignment of metal–organic framework crystals in specific crystallographic orientations

“…[30][31][32][33][34] The combination of metal nodes and organic linkers allows for the creation of customizable pore structures within ordered arrangements, [1][2][3]5,6,35 catering to specific application requirements. [36][37][38] Over the past three decades, researchers have developed various strategies to tailor the properties of MOFs, such as exploring novel MOF structures, 39 conducting post-synthetic modifications, [40][41][42][43][44][45][46][47] and incorporating composites. 48 Recently, a promising method called MOF crystal alignment has emerged, enhancing MOF properties without the need for new structural designs or postsynthetic reactions.…”

Multivariate Metal–Organic Frameworks Ranging from a Homogeneous Uniform Distribution to Heterogeneous 1D, 2D, and 3D Distributions of Mixed Building Blocks

“…Both the diffusion of incoming building blocks and the exchange are affected by factors such as solvents, reaction temperatures, and concentrations of incoming building blocks but to different extents. As a result, the spatial distribution of the two types of building blocks within the entire MOF crystals can be modulated by managing these factors during the PSE process. − However, most studies have focused on the PSE process in isotropic 3D MOFs transforming into isostructural 3D MOFs. These transformations usually involve minimal reorganization of the framework structures.…”