Role of Solvent-Host Interactions That Lead to Very Large Swelling of Hybrid Frameworks

Abstract

An unusually large expansion upon solvent adsorption occurs without apparent bond breaking in the network of a series of isoreticular chromium(III) or iron(III) diarboxylates labeled MIL-88A to D [dicarbox = fumarate (88A); terephthalate (1,4-BDC) (88B); 2,6-naphthalenedicarboxylate (2,6-NDC) (88C); and 4-4'-biphenyldicarboxylate (4-4'-BPDC) (88D)]. This reversible "breathing" motion was analyzed in terms of cell dimensions (extent of breathing), movements within the framework (mechanism of transformation), and the interactions between the guests and the skeleton. In situ techniques show that these flexible solids are highly selective absorbents and that this selectivity is strongly dependent on the nature of the organic linker.

A New Family of Bimetallic Framework Materials Showing Reversible Structural Transformations

“…The crystal structure analysis of ([Cd(tn)] 3 [Cr(CN) 6 ] 2 ) ∞ (2) revealed that it is also a three-dimensional network with both (15) Å, which is usual for six coordinated CdN 6 . 52 Again the structure can be described as being formed of hexametallocycles consisting of only Cd1 atoms and tn ligands.…”

“…[23][24][25][26][27][28] Some cyanide-bridged inorganic coordination polymers, prepared by assembling cyanometalate anions and transition metal complexes as building blocks, have also been found to have framework structures. The hexacyanometalates, M II (CN) 6 4-and M III (CN) 6 3-, are good building blocks, and a number of multidimensional systems have been synthesized, some with interesting magnetic properties. [29][30][31][32][33][34] Interest in the gas sorption properties of these compounds has increased in recent years.…”

“…43 Our interests are in the construction of materials, porous or not, in which such phase transformations take place. 44 Here we report on three new 3D metal-organic cyano-bridged frameworks, prepared in a very simple manner from the ligand 1,3-diaminopropane (tn), the hexacyanometalates [Co(CN) 6 4 : M ) Cd 2+ , Cu 2+ ). In order to explore their potential adsorptive properties and to study the various phase transformations that take place, the techniques of immersion calorimetry and in situ powder X-ray diffraction have been used.…”

“…[1][2][3][4][5][6][7][8] These compounds are of great interest owing to their potential applications in the areas of gas storage, gas separation, and heterogeneous catalysis. [9][10][11][12][13][14][15][16][17][18][19][20][21][22] The majority of these compounds are homometallic and have been formed using organic carboxylates and transition metal salts.…”

Series of Highly Stable Isoreticular Lanthanide Metal–Organic Frameworks with Expanding Pore Size and Tunable Luminescent Properties

“…The most common approach to synthesize isoreticular MOFs with different pore sizes is to combine metal clusters and organic linkers of various sizes. This has been demonstrated by combining metal clusters with ditopic linkers such as in the IRMOF-n series with tetrameric Zn clusters, 9 the MIL-88 10 and MIL-101 11,12 series with trimetric metal clusters, and the UiO-66 series with hexameric Zr clusters. 13 Isoreticular MOFs have also been synthesized by combining metal clusters with tritopic linkers, such as in the HKUST-1 series with dimeric metal paddle-wheel clusters 14−17 and the MIL-100 series 11,18 with trimeric metal clusters.…”