Benzene‐Templated Hydrothermal Synthesis of Metal–Organic Frameworks with Selective Sorption Properties

Abstract

In this paper, we report two metal-organic frameworks [Co3(ndc)3(bipyen)(1.5)]H2O (1) and [Co2(ndc)2bipyen)]C6H6.H2O (2) (bipyen=trans-1,2-bis(4-pyridyl)ethylene, H2ndc=2,6-naphthalenedicarboxylic acid). These compounds were both synthesized from identical hydrothermal reaction conditions except that benzene was added to the reaction for 2. Crystal structures show that the two compounds have triply interpenetrated three-dimensional frameworks and these frameworks have the same primary structure of a two-dimensional network of interconnected [Co2(O2CR)(4/2)] (R=naphthalene group) paddle-wheels and bridging bipyen ligands. Both compounds have guest water molecules and, in addition, 2 has guest benzene molecules. Structural transformations of the host accompanied guest removal, which can be monitored by powder X-ray diffraction. N2 adsorption data of 2 show that there are two different types of pores corresponding to the benzene and water pores. Upon exposure to vapors of several organic molecules, the heat-treated sample of 2 adsorbs benzene and cyclohexene, but does not adsorb toluene, (o-, m-, and p-)xylenes, cycloheptatriene, or cyclohexane.

Investigation of hybrid molecular material prepared by ionic liquid and polyoxometalate anion

“…Figure 2 shows the powder X-ray diffraction (PXRD) pattern of pure hydrated phosphotungstic acid and 1-butyl 3-methyl imidazolium phosphotungstate hybrid material, [ 12 This type of host-guest interactions are known to bring about the structural transformations which are detected by powder X-ray diffraction. 21 The intense peak at 2θ = 9⋅4 in the PXRD pattern seems to indicate that the compound may have layered type of structure.…”

Adsorption of water on three-dimensional pillared-layer metal organic frameworks

“…Gas sorptivity of many MOFs has been energetically researched [7][8][9][10][11][12][13][14][15][16][17][18][19][20] and some reports showed an excellent gas sorption ability which is comparable with or exceeds that of carbon materials or zeolite [20][21][22][23][24][25]. For example, Yaghi et al reported zeolite-like MOFs that have high surface area (over 3000 m 2 g −1 ) and porosity [20,21].…”

Chemistry and application of flexible porous coordination polymers

“…Moreover, the solvent can function as a template for constructing the framework and also prohibits catenation, enabling the formation of an open structure. For example, the compounds figure 1), are good examples of the effect of solvent on the synthesis of PCPs [40]. Hydrothermal reactions of both compounds were carried out under similar conditions except that a benzene molecule was added to the mother liquor of the latter one.…”