synthesis-of-single-crystalline-core-shell-metal-organic-frameworks

Synthesis of Single-Crystalline Core-Shell Metal-Organic Frameworks

Because of their designability and unprecedented synergistic effects, core-shell metal-organic frameworks (MOFs) have been actively examined recently. ...

Ulsan National Institute of Science and Technology (UNIST)

Composite metal-organic frameworks (MOFs) tend to possess complex interfaces that prevent facile and rational design. Here we present a joint computational/experimental workflow that screens thousands of MOFs and identifies the optimal MOF pairs that can seamlessly connect to one another by taking advantage of the fact that the metal nodes of one MOF can form coordination bonds with the linkers of the second MOF. Six MOF pairs (HKUST-1@MOF-5, HKUST-1@IRMOF-18, UiO-67@HKUST-1, PCN-68@MOF-5, UiO-66@MIL-88B(Fe) and UiO-67@MIL-88C(Fe)) yielded from our theoretical predictions were successfully synthesized, leading to clean single crystalline MOF@MOF, demonstrating the power of our joint workflow. Our work can serve as a starting point to accelerate the discovery of novel MOF composites that can potentially be used for many different applications.

Computer-aided discovery of connected metal-organic frameworks.

An isotope-selective responsive system based on molecular recognition in porous materials has potential for the storage and purification of isotopic mixtures but is considered unachievable because of the almost identical physicochemical properties of the isotopes. Herein, a unique isotope-responsive breathing transition of the flexible metal-organic framework (MOF), MIL-53(Al), which can selectively recognize and respond to only D molecules through a secondary breathing transition, is reported. This novel phenomenon is examined using  neutron diffraction experiments under the same conditions for H and D sorption experiments. This work can guide the development of a novel isotope-selective recognition system and provide opportunities to fabricate flexible MOF systems for energy-efficient purification of the isotopic mixture.

Specific Isotope-Responsive Breathing Transition in Flexible Metal-Organic Frameworks.

Hydrogen isotope separation with nanoporous materials is a very challenging yet promising approach. To overcome the limitation of the conventional isotope separation strategy, quantum sieving-based separation using nanoporous materials has been investigated recently. In this study, to see the thermodynamic deuterium separation phenomena attributed to the chemical affinity quantum sieving effect, we examine Hofmann-type metal-organic frameworks (MOFs), Co(pyz)[M(CN)] (pyz = pyrazine, M = Pd, Pt, and Ni), which have microporosity (4.0 × 3.9 Å) and an extraordinarily high density of open metal sites (∼9 mmol/cm). Owing to the preferential adsorption of D over H at strongly binding open metal sites, the Hofmann-type MOF, Co(pyz)[Pd(CN)] exhibited a high selectivity () of 21.7 as well as a large D uptake of 10 mmol/g at 25 K. This is the first study of Hofmann-type MOFs to report high selectivity and capacity, both of which are important parameters for the practical application of porous materials toward isotope separation.

Article	Year
Computer-aided discovery of connected metal-organic frameworks. Nature communications\| PubMed ID: 31399593	2019
Specific Isotope-Responsive Breathing Transition in Flexible Metal-Organic Frameworks. Journal of the American Chemical Society\| PubMed ID: 32649827	2020
Thermodynamic Separation of Hydrogen Isotopes Using Hofmann-Type Metal-Organic Frameworks with High-Density Open Metal Sites. ACS applied materials & interfaces\| PubMed ID: 35735059	2022

Junsu Ha

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