Highly Selective Adsorption of Perfluorinated Greenhouse Gases by Porous Organic Cages

Abstract

Anthropogenic greenhouse gases contribute to global warming. Among those gases, perfluorocarbons (PFCs) are thousands to tens of thousands of times more harmful to the environment than comparable amounts of carbon dioxide. To date, materials that selectively adsorb perfluorocarbons in favor of other less harmful gases have not been reported. Here, a series of porous organic cage compounds with alkyl‐, fluoroalkyl‐, and partially fluorinated alkyl groups is presented. Their isomorphic crystalline states allow the study of the structure–property relationship between the degree of fluorination of the alkyl chains and the gas sorption properties for PFCs and their selective uptakes in comparison to other, nonfluorinated gases. By this approach, one compound having superior selectivities of PFCs versus N2 or CO2 under ambient conditions is identified.

Amino-Functionalized Microporous MOFs for Capturing Greenhouse Gases CF4 and NF3 with Record Selectivity

“…This is because NH 2 − Ni-MOF possesses a smaller ultra-micropore and stronger affinity to CF 4 molecules, thus leading to higher selectivity. To the best of our knowledge, this selectivity of CF 4 /N 2 (1/9) in NH 2 −Ni-MOF is the highest in all reported porous materials for CF 4 /N 2 separation (Figure 4e and Table S2), such as PAF-4F (4.68), 37 F-cage (4.04), 38 New-PAF-1 (∼5), 39 and Cu(peba) 2 (2.25), 40 notably higher than that of the benchmark C-PVDC-600 (18.6). 25 Ni-MOF and NH 2 −Ni-MOF eliminate the tradeoff between the separation selectivity and adsorption capacity (Figure 4e).…”

An Organic Molecular Nanobarrel that Hosts and Solubilizes C60

“…[2] The structure of the framework generates a well‐defined internal cavity and also windows of different shapes and dimensions that allow entering and exiting the cavity. Owing to these structural features, organic cages present many opportunities as molecular hosts and porous materials, which have a lot of potential in several applications including encapsulation,[ 2a , 3 ] molecular reaction vessels,[ 3a , 4 ] separations,[ 3b , 5 ] and sensing, [6] among others.…”

A highly permeable porous organic cage composite membrane for gas separation

“…In the study of Guan et al, 30 Different from these extended porous framework structures, porous organic cages (POCs) are isolated molecules with intrinsic cavities that pack and assemble through intermolecular forces to form structurally stable porous solids 31 and possess the advantage of being reprocessable in solution. Therefore, these characteristics enable POCs to realize functionalities and customized properties through reasonable design, thereby being a recent research hotspot in the elds of ion separation, 32,33 gas separation, [34][35][36][37] molecular sieving, 38 and catalysis. 39,40 As a kind of POC, CC3 organic cages were rst synthesized by Cooper's team through the dehydration condensation of aldehyde and amine [4 + 6] to generate imine bonds.…”