Abstract
Metal–organic framework (MOF) materials are known to be amenable to expansion through elongation of the parent organic linker. For a family of model (3,24)-connected MOFs with the rht topology, in which the central part of organic linker comprises a hexabenzocoronene unit, the effect of the linker type and length on their structural and gas adsorption properties is studied computationally. The obtained results compare favorably with known MOF materials of similar structure and topology. We find that the presence of a flat nanographene-like central core increases the geometric surface area of the frameworks, sustains additional benzene rings, and promotes linker elongation and the efficient occupation of the void space by guest molecules. This provides a viable linker modification method with potential for enhancement of uptake for methane and other gas molecules.
Highlights
A family of model Metal-organic framework (MOF) based on the (3,24)-connected MOF networks with the rht topology has been proposed in which the central part of the organic linker has been replaced with hexabenzocoronene molecule
It has been shown that a replacement of the central linker fragment with hexabenzocoronene molecule increases the size and, in some cases, gas uptake capability of the MOFs family with rhtnetwork topology
Grand Canonical Monte Carlo (GCMC) simulations of CH4 uptake have been performed on the optimised MOF structures at pressures up to 70 bar and at two temperature values, T = 273 K and 298 K
Summary
Crystalline nanoporous networks such as metal-organic frameworks (MOFs) with tuneable pore geometry and designed chemical functionality[1,2] are attracting a great deal of interest as promising materials for a wide range of applications including light harvesting,[3,4] drug delivery,[5] biomedical imaging,[6] catalysis,[7,8,9] chemical sensing,[10] gas separation and storage.[11,12,13,14,15,16,17,18] MOFs are compounds containing metal nodes (metal ions or clusters) coordinated to organic linker molecules that form the extended network structures with unique physical and chemical properties. Martin and Haranczyk have suggested[32,33,34] an alternative strategy for computational design of the optimal organic ligand leading to an efficient occupation of the internal volume by guest molecules In this approach, organic ligands are replaced by purely geometrical “building blocks” described by a number of variable parameters, which were optimized to predict and iteratively refine the resulting MOF structure. A similar computational strategy has been adopted previously by Fairen-Jimenez et al.[35] in the study of hydrogen adsorption in hypothetical MOFs with the rht-topology
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
