Continuous fractional component Monte Carlo simulations of high-density adsorption in metal–organic frameworks

<div><p>The continuous fractional component Monte Carlo method, which was designed to overcome difficulties with insertions and deletions of molecules, is modified to include configurational bias Monte Carlo methods and is further extended to binary systems. The modified method is shown to correctly predict adsorption of Ar in silicalite, Xe and Kr in HKUST-1, and enantiomers in a homochiral metal–organic framework. The modified method is also found to be approximately an order of magnitude more efficient in inserting and deleting molecules than traditional configurational bias grand canonical Monte Carlo simulations in dense systems.</p></div

Highly Selective Carbon Dioxide Uptake by [Cu(bpy-<i>n</i>)₂(SiF₆)] (bpy-1 = 4,4′-Bipyridine; bpy-2 = 1,2-Bis(4-pyridyl)ethene)

A previously known class of porous coordination polymer (PCP) of formula [Cu­(bpy-<i>n</i>)₂(SiF₆)] (bpy-1 = 4,4′-bipyridine; bpy-2 = 1,2-bis­(4-pyridyl)­ethene) has been studied to assess its selectivity toward CO₂, CH₄, N₂, and H₂O. Gas sorption measurements reveal that [Cu­(bpy-1)₂(SiF₆)] exhibits the highest uptake for CO₂ yet seen at 298 K and 1 atm by a PCP that does not contain open metal sites. Significantly, [Cu­(bpy-1)₂(SiF₆)] does not exhibit particularly high uptake under the same conditions for CH₄, N₂, and, H₂O, presumably because of its lack of open metal sites. Consequently, at 298 K and 1 atm [Cu­(bpy-1)₂(SiF₆)] exhibits a relative uptake of CO₂ over CH₄ of <i>ca</i>. 10.5:1, the highest value experimentally observed in a compound without open metal sites. [Cu­(bpy-2)₂(SiF₆)] exhibits larger pores and surface area than [Cu­(bpy-1)₂(SiF₆)] but retains a high CO₂/CH₄ relative uptake of <i>ca</i>. 8:1

Highly Selective Carbon Dioxide Uptake by [Cu(bpy-<i>n</i>)₂(SiF₆)] (bpy-1 = 4,4′-Bipyridine; bpy-2 = 1,2-Bis(4-pyridyl)ethene)

A previously known class of porous coordination polymer (PCP) of formula [Cu­(bpy-<i>n</i>)₂(SiF₆)] (bpy-1 = 4,4′-bipyridine; bpy-2 = 1,2-bis­(4-pyridyl)­ethene) has been studied to assess its selectivity toward CO₂, CH₄, N₂, and H₂O. Gas sorption measurements reveal that [Cu­(bpy-1)₂(SiF₆)] exhibits the highest uptake for CO₂ yet seen at 298 K and 1 atm by a PCP that does not contain open metal sites. Significantly, [Cu­(bpy-1)₂(SiF₆)] does not exhibit particularly high uptake under the same conditions for CH₄, N₂, and, H₂O, presumably because of its lack of open metal sites. Consequently, at 298 K and 1 atm [Cu­(bpy-1)₂(SiF₆)] exhibits a relative uptake of CO₂ over CH₄ of <i>ca</i>. 10.5:1, the highest value experimentally observed in a compound without open metal sites. [Cu­(bpy-2)₂(SiF₆)] exhibits larger pores and surface area than [Cu­(bpy-1)₂(SiF₆)] but retains a high CO₂/CH₄ relative uptake of <i>ca</i>. 8:1

Highly Selective Carbon Dioxide Uptake by [Cu(bpy-<i>n</i>)₂(SiF₆)] (bpy-1 = 4,4′-Bipyridine; bpy-2 = 1,2-Bis(4-pyridyl)ethene)

A previously known class of porous coordination polymer (PCP) of formula [Cu­(bpy-<i>n</i>)₂(SiF₆)] (bpy-1 = 4,4′-bipyridine; bpy-2 = 1,2-bis­(4-pyridyl)­ethene) has been studied to assess its selectivity toward CO₂, CH₄, N₂, and H₂O. Gas sorption measurements reveal that [Cu­(bpy-1)₂(SiF₆)] exhibits the highest uptake for CO₂ yet seen at 298 K and 1 atm by a PCP that does not contain open metal sites. Significantly, [Cu­(bpy-1)₂(SiF₆)] does not exhibit particularly high uptake under the same conditions for CH₄, N₂, and, H₂O, presumably because of its lack of open metal sites. Consequently, at 298 K and 1 atm [Cu­(bpy-1)₂(SiF₆)] exhibits a relative uptake of CO₂ over CH₄ of <i>ca</i>. 10.5:1, the highest value experimentally observed in a compound without open metal sites. [Cu­(bpy-2)₂(SiF₆)] exhibits larger pores and surface area than [Cu­(bpy-1)₂(SiF₆)] but retains a high CO₂/CH₄ relative uptake of <i>ca</i>. 8:1

Computation-Ready, Experimental Metal–Organic Frameworks: A Tool To Enable High-Throughput Screening of Nanoporous Crystals

Experimentally refined crystal structures for metal–organic frameworks (MOFs) often include solvent molecules and partially occupied or disordered atoms. This creates a major impediment to applying high-throughput computational screening to MOFs. To address this problem, we have constructed a database of MOF structures that are derived from experimental data but are immediately suitable for molecular simulations. The computation-ready, experimental (CoRE) MOF database contains over 4700 porous structures with publically available atomic coordinates. Important physical and chemical properties including the surface area and pore dimensions are reported for these structures. To demonstrate the utility of the database, we performed grand canonical Monte Carlo simulations of methane adsorption on all structures in the CoRE MOF database. We investigated the structural properties of the CoRE MOFs that govern methane storage capacity and found that these relationships agree well with those derived recently from a large database of hypothetical MOFs