Porous Coordination‐Polymer Crystals with Gated Channels Specific for Supercritical Gases

An Interpenetrated Framework Material with Hysteretic CO2 Uptake

“…Similar behavior has been reported for the adsorption of nitrogen by a two-dimensional framework material [35] and by a three-dimensional pillared paddlewheel structure, but is otherwise unknown. [20,36] The N 2 and Ar isotherms of YO-MOF display a fairly unusual gated adsorption behavior (see Figure 4 and the Supporting Information). Interestingly, there is virtually no adsorption until the gate pressure, at which point there is an abrupt increase in adsorption.…”

“…[9] The ability to effect guest-responsive structural behavior in traditionally crystalline MOF materials is becoming more apparent. [10][11][12][13][14][15][16][17][18] However, very few of these reports examine threedimensional frameworks, [19] even fewer investigate catenated structures, [20] and most often, the reported flexible behavior is observed only at high pressure. A guest-responsive, structurally flexible porous material that demonstrates dynamic performance under more subtle conditions of pressure and temperature could have application potential in gas separations or as a highly selective sensor of molecular adsorbates.…”

Chemical and Physical Solutions for Hydrogen Storage

“…[21,22] This form of adsorption relies on the flexibility of the framework of some MOFs; that is, the structure expands upon adsorption of guest species, and shrinks again upon desorption. This typically leads to a rather pronounced hysteresis, which can be used to load the materials at high pressures and still capture the hydrogen at lower pressure or at somewhat higher temperature.…”

How Hydration Drastically Improves Adsorption Selectivity for CO2 over CH4 in the Flexible Chromium Terephthalate MIL‐53

“…Such structures possess tunnels or cavities with pore sizes between 3 and 35 . Several of these organic-inorganic hybrid porous solids [4][5][6][7][8][9][10][11] have the interesting feature of being selectively flexible during the adsorption process by means of a breathing [12] or gate-opening process, [9] which depends on the nature of the adsorptive. Examples discovered by Ferey and coworkers include flexible porous carboxylates formed by chains of metallic centers (MIL-53, -69) [13,14] and with metalcenter trimers (MIL-88A).…”