A Charged Coordination Cage-Based Porous Salt

Abstract

Metal–organic frameworks and porous coordination cages have shown incredible promise as a result of their high tunability. However, syntheses pursuing precisely targeted mixed functionalities, such as multiple ligand types or mixed-metal compositions are often serendipitous, require postsynthetic modification strategies, or are based on complex ligand design. Herein, we present a new method for the controlled synthesis of mixed functionality metal–organic materials via the preparation of porous salts. More specifically, the combination of porous ionic molecules of opposite charge affords framework-like materials where the ratio between cationic cage and anionic cage is potentially tunable. The resulting doubly porous salt displays the spectroscopic signatures of the parent cages with increased gas uptake capacities as compared to starting materials. This approach will be widely applicable to all families of porous ions and represents a new and powerful method for the synthesis of porous solids with tailored functionalities.

Control of extrinsic porosities in linked metal-organic polyhedra gels by imparting coordination-driven self-assembly with electrostatic repulsion

“…Metal-organic polyhedra (MOPs), a class of discrete coordination cages with well-defined internal cavities, have emerged as microporous building blocks for the construction of extended porous architectures due to their good solubility and designable outer periphery available for further connection. [1][2] By crosslinking MOPs with ditopic linkers [3][4] or tuning the noncovalent interaction between them (hydrogen bonding, [5][6] electrostatic interaction [7][8] and host-guest interaction, [9][10] for instance), various multidimensional assemblies are synthesized, ranging from crystalline porous solids like metal-organic frameworks (MOFs) 11 to amorphous soft materials such as films [12][13] or gels. [14][15][16] Considering practical applications, the latter has attracted increasing interests because of their potentials for realizing processable microporous materials.…”

Synthesis of Polycarboxylate Rhodium(II) Metal–Organic Polyhedra (MOPs) and their use as Building Blocks for Highly Connected Metal–Organic Frameworks (MOFs)

“…These characteristics have been recently exploited for the synthesis of porous amorphous soft materials, wherein MOPs are connected through flexible N,N′‐based linkers using the peripheral axial positions of their constituent paddle‐wheel units [4] . Additionally, porous crystalline salts have been assembled from the electrostatic interaction of oppositely charged MOPs [5] . In metal‐organic frameworks (MOFs), MOPs are used for the rational construction of highly‐connected nets following the well‐known supermolecular building block (SBB) approach [6, 7] .…”

Crystalline Porous Organic Salts: From Micropore to Hierarchical Pores

“…For this purpose, supramolecular cages or cavities with intrinsic larger porosity as a promising building unit has been attempted to create crystalline organic salts with a larger pore size. [52,80,82,84] Ward and co-workers reported the synthesis of a quasi-truncated octahedron (q-TO) built from molecular tiles joining at their edges through two types of hydrogen bonds. [52] Then, from q-TO units a bodycentered cubic framework with zeolitic architecture was constructed.…”