Discovery and introduction of a (3,18)-connected net as an ideal blueprint for the design of metal–organic frameworks

Abstract

Metal-organic frameworks (MOFs) are a promising class of porous materials because it is possible to mutually control their porous structure, composition and functionality. However, it is still a challenge to predict the network topology of such framework materials prior to their synthesis. Here we use a new rare earth (RE) nonanuclear carboxylate-based cluster as an 18-connected molecular building block to form a gea-MOF (gea-MOF-1) based on a (3,18)-connected net. We then utilized this gea net as a blueprint to design and assemble another MOF (gea-MOF-2). In gea-MOF-2, the 18-connected RE clusters are replaced by metal-organic polyhedra, peripherally functionalized so as to have the same connectivity as the RE clusters. These metal-organic polyhedra act as supermolecular building blocks when they form gea-MOF-2. The discovery of a (3,18)-connected MOF followed by deliberate transposition of its topology to a predesigned second MOF with a different chemical system validates the prospective rational design of MOFs.

In situ X-ray diffraction monitoring of a mechanochemical reaction reveals a unique topology metal-organic framework

“…In the context of understanding mechanochemical reactivity, the described results are an important advance as the ARTICLE first direct observation of an amorphization-recrystallization mechanism in mechanosynthesis and the first evidence of a metastable, structurally unusual intermediate in a mechanochemical process. The ability to use mechanochemical reaction monitoring to discover a new net topology in a system that has so far been subject to hundreds of studies is of outstanding importance in solid-state chemistry, and especially in the area of metal-organic frameworks 39 . Thus, our findings highlight the role of in situ and real-time PXRD monitoring as a complement to other experimental and computational studies of the structural landscape of metal-organic frameworks 40,41 .…”

Low concentration CO2 capture using physical adsorbents: Are metal–organic frameworks becoming the new benchmark materials?

“…18 It is then to be expected that large scale implementation of MOFs will take at least the same time frame. The huge choice of inorganic clusters and organic linkers for MOFs fabrication suggest that they can be easily tuned unlike activated carbon and zeolites, although it is often very difficult to predict the structures of MOFs 19,20 and the effects of their functionalization before synthesis. Overall, work on the rational design, development and synthesis of MOFs that target particular applications remains scarce.…”

“…Overall, work on the rational design, development and synthesis of MOFs that target particular applications remains scarce. [20][21][22][23][24] To evaluate the performance of various adsorbents, we selected a series of materials from each family to compare their adsorption properties in terms of porosity, gravimetric/volumetric uptake (at low CO 2 concentrations up to 50 % and a total pressure of 1 bar, in balance with N 2 and CH 4 and H 2 ), energetics, selectivity, stability and tolerance to water vapor. We also describe the physical separation mechanisms involved in the most promising CO 2 adsorbents.…”

Nets, tiles, and metal-organic frameworks

“…4 These can be targets of designed synthesis as in a recent spectacular synthesis of MOFs based on the (3,18)-c net gea with transitivity 2 2. 23 We include these under the heading of minimal transitivity nets.…”