Bottom-up construction of a superstructure in a porous uranium-organic crystal

Abstract

Bottom-up construction of highly intricate structures from simple building blocks remains one of the most difficult challenges in chemistry. We report a structurally complex, mesoporous uranium-based metal-organic framework (MOF) made from simple starting components. The structure comprises 10 uranium nodes and seven tricarboxylate ligands (both crystallographically nonequivalent), resulting in a 173.3-angstrom cubic unit cell enclosing 816 uranium nodes and 816 organic linkers-the largest unit cell found to date for any nonbiological material. The cuboctahedra organize into pentagonal and hexagonal prismatic secondary structures, which then form tetrahedral and diamond quaternary topologies with unprecedented complexity. This packing results in the formation of colossal icosidodecahedral and rectified hexakaidecahedral cavities with internal diameters of 5.0 nanometers and 6.2 nanometers, respectively-ultimately giving rise to the lowest-density MOF reported to date.

Designing Hydrogen‐Bonded Organic Frameworks (HOFs) with Permanent Porosity

“…Construction of HOFs with permanent porosity requires acombination of noncovalent intermolecular interactions,such as pp interactions,with H-bonds,because H-bonding alone is too weak to maintain low-density porous materials compared with dative and covalent bonds. [14] Thef ollowing Sections (Sections 2.1-2.4) describe supramolecular synthons and tectons reported to be useful for designing HOFs with permanent porosity.…”

Two New Coordination Polymers with UO22+ Units and Fluorinated Aromatic Carboxylate Linkers

“…Among the uranyl(VI) containing MOFs NU‐1301 is probably the most spectacular one. This giant MOF with a 173.3 Å cubic unit cell consists of 816 uranium nodes and 816 methyl‐substituted BTB linkers (BTB: 4,4',4''‐benzene‐1,3,5‐triyl‐tribenzoate) giving rise to a highly porous crystal structure with cavities of an internal diameter up to 62 Å . In a recent review Shustova and co‐workers analysed more than 100 crystal structures of actinide‐based MOFs .…”

Robust Microporous Metal–Organic Frameworks for Highly Efficient and Simultaneous Removal of Propyne and Propadiene from Propylene

“…However, the use of traditional porous materials,s uch as zeolites, [5,6] and activated carbon [7] to separate ternary propyne/propadiene/ propylene gas mixtures has not been realized yet, possibly because of the similar physical properties,s tructure,a nd molecular sizes of propyne,p ropadiene,a nd propylene (Scheme 1). [9][10][11][12][13] Much effort has been devoted to the use of MOFs for the separation of binary gas mixtures, such as acetylene/ethylene, [14][15][16][17][18][19] ethylene/ethane, [14,[20][21][22] carbon dioxide/methane, [23,24] carbon dioxide/nitrogen, [25,26] acetylene/carbon dioxide, [27,28] krypton/xenon, [29] propyne/ propylene, [30,31] and propylene/propane. monotonous structure,l ack of specific binding sites) owing to their welldefined structure,f ine-tunable pore size,a nd customdesigned functional groups.…”