A Three-Dimensional Dynamic Metal–Organic Framework with Fourfold Interpenetrating Diamondoid Networks and Selective Adsorption Properties

Abstract

A three-dimensional metal-organic framework (1) with fourfold interpenetrating diamondoid networks was constructed using a macrocyclic nickel(II) complex and a tetracarboxylic ligand 4,4',4″,4‴-(cyclohexane-1,2-diyibis(azanetriyl))tetrakis(methylene)tetrabenzoic acid as building blocks. Despite the fourfold interpenetration, 1 possesses one-dimensional channels that are occupied by water and CH3CN guest molecules. Once the guest molecules were removed, the framework and pores in desolvated 1 are dynamic with large adsorption hysteresis loops, which exhibit selective gas adsorption for CO2 at 195 K over N2 and H2 at 77 K and selective adsorption for methanol, ethanol, and n-propanol over isopropanol at 298 K.

Water-alcohol adsorptive separations using metal-organic frameworks and their composites as adsorbents

“…Some other synthetic strategies for designing MOFs applicable in water-alcohol adsorptive separations focus on utilizing specific interactions between MOFs and adsorbate molecules [67], micro-porous MOFs [68][69][70][71][72][73][74], and MOFs with 1D channels and molecular gates, which can only open for specific adsorbate molecules [75,76].…”

“…Even though the difference in the molecular size of water, methanol and ethanol is very small, significant research is still devoted to the design of size-selective microporous MOFs for the separation of wateralcohol mixtures [68][69][70][71][72][73][74]. The ligands used for the synthesis of such microporous MOFs are shown in Fig.…”

“…Micropores formation may also result from the interpenetration of highly porous frameworks. For example, [(NiY) 4 (CDTA) 2 ]⋅ 2.5CH 3 CN⋅22H 2 O (H 4 CDTA ¼ 4,4 0 ,4 00 ,4 000 -(cyclohexane-1,2-diylbis(azanetriyl))tetrakis(methylene)tetrabenzoic acid) is built up from a macrocyclic nickel cluster [NiY] 2þ and a semirigid linker [74]. It has a fourfold interpenetrated framework (Fig.…”

“…It has a fourfold interpenetrated framework (Fig. 12) with 1D pores having a size of about 6 � 8 Å 2 [74]. This MOF shows a selective adsorption for methanol and ethanol over n-propanol and isopropanol (Fig.…”

Different Benzendicarboxylate-Directed Structural Variations and Properties of Four New Porous Cd(II)-Pyridyl-Triazole Coordination Polymers

“…And the desorption process also displays the several steps at the corresponding points. As a result, the large hysteresis loops happen, leading that the CH 4 is packed in the structure at the lower pressures and not released right now on decreasing the external pressure (Liu et al, 2013;Handke et al, 2014;Ju et al, 2015;Hiraide et al, 2017;Sun et al, 2017).…”