Porous Colloidal Hydrogels Formed by Coordination-Driven Self-Assembly of Charged Metal-Organic Polyhedra

Introduction of porosity into supramolecular gels endows soft materials with functionalities for molecular encapsulation, release, separation and conversion. Metal-organic polyhedra (MOPs), discrete coordination cages containing an internal cavity, have recently been employed as building blocks to construct polymeric gel networks with potential porosity. However, most of the materials can only be synthesized in organic solvents, and the examples of porous, MOP-based hydrogels are scarce. Here, we demonstrate the fabrication of porous hydrogels based on [Rh2(OH-bdc)2]12, a rhodium-based MOP containing hydroxyl groups on its periphery (OH-bdc = 5-hydroxy-1,3-benzenedicarboxylate). By simply deprotonating [Rh2(OH-bdc)2]12 with the base NaOH, the supramolecular polymerization between MOPs and organic linkers can be induced in the aqueous solution, leading to the kinetically controllable formation of hydrogels with hierarchical colloidal networks. When heating the deprotonated MOP, Nax[Rh24(O-bdc)x(OH-bdc)24-x], to induce gelation, the MOP was found to partially decompose, affecting the mechanical property of the resulting gels. By applying a post-synthetic deprotonation strategy, we show that the deprotonation degree of the MOP can be altered after the gel formation without serious decomposition of the MOPs. Gas sorption measurements confirmed the permanent porosity of the corresponding aerogels obtained from these MOP-based hydrogels, showing potentials for applications in gas sorption and catalysis.

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Control of extrinsic porosities in linked metal-organic polyhedra gels by imparting coordination-driven self-assembly with electrostatic repulsion

10.26434/chemrxiv-2022-8gbb1 ◽

2022 ◽

Author(s):

Zaoming Wang ◽

Takuma Aoyama ◽

Eli Sanchez-Gonzales ◽

Tomoko Inose ◽

Kenji Urayama ◽

...

Keyword(s):

Self Assembly ◽

Molecular Level ◽

Amorphous State ◽

Soft Materials ◽

Internal Cavity ◽

Hydroxyl Groups ◽

Electrostatic Repulsion ◽

Outer Periphery ◽

Metal Organic

The linkage of metal-organic polyhedra (MOPs) for the synthesis of porous soft materials is one of the promising strategies to combine processability with permanent porosity. Compared to the defined internal cavity of MOPs, it is still difficult to control the extrinsic porosities generated between crosslinked MOPs because of their random arrangements in their networks. Herein, we report a method to form linked MOP gels with controllable extrinsic porosities by introducing negative charges on the surface of MOPs that facilitates electrostatic repulsion between them. A hydrophilic rhodium-based cuboctahedral MOP (OHRhMOP) with 24 hydroxyl groups on its outer periphery can be controllably deprotonated to impart the MOP with tunable electrostatic repulsion in solution. This electrostatic repulsion between MOPs stabilizes the kinetically trapped state, in which a MOP is coordinated with various bisimidazole linkers in a monodentate fashion at a controllable link-er/MOP ratio. The heating of the kinetically trapped molecules leads to the formation of gels with similar colloidal networks but different extrinsic porosity. This strategy allows us to design the molecular-level networks and the resulting porosities even in the amorphous state.

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Inverse Design of Nanoporous Crystalline Reticular Materials with Deep Generative Models

10.26434/chemrxiv.12186681.v1 ◽

2020 ◽

Cited By ~ 3

Author(s):

Zhenpeng Yao ◽

Benjamin Sanchez-Lengeling ◽

N. Scott Bobbitt ◽

Benjamin J. Bucior ◽

Sai Govind Hari Kumar ◽

...

Keyword(s):

Self Assembly ◽

Metal Organic Framework ◽

Internal Surface ◽

Building Blocks ◽

Structural Features ◽

Generative Models ◽

Combinatorial Design ◽

Surface Areas ◽

Molecular Building Blocks ◽

Metal Organic

Reticular frameworks are crystalline porous materials that form via the self-assembly of molecular building blocks (i.e., nodes and linkers) in different topologies. Many of them have high internal surface areas and other desirable properties for gas storage, separation, and other applications. The notable variety of the possible building blocks and the diverse ways they can be assembled endow reticular frameworks with a near-infinite combinatorial design space, making reticular chemistry both promising and challenging for prospective materials design. Here, we propose an automated nanoporous materials discovery platform powered by a supramolecular variational autoencoder (SmVAE) for the generative design of reticular materials with desired functions. We demonstrate the automated design process with a class of metal-organic framework (MOF) structures and the goal of separating CO2 from natural gas or flue gas. Our model exhibits high fidelity in capturing structural features and reconstructing MOF structures. We show that the autoencoder has a promising optimization capability when jointly trained with multiple top adsorbent candidates identified for superior gas separation. MOFs discovered here are strongly competitive against some of the best-performing MOFs/zeolites ever reported. This platform lays the groundwork for the design of reticular frameworks for desired applications.

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Inverse Design of Nanoporous Crystalline Reticular Materials with Deep Generative Models

10.26434/chemrxiv.12186681 ◽

2020 ◽

Author(s):

Zhenpeng Yao ◽

Benjamin Sanchez-Lengeling ◽

N. Scott Bobbitt ◽

Benjamin J. Bucior ◽

Sai Govind Hari Kumar ◽

...

Keyword(s):

Self Assembly ◽

Metal Organic Framework ◽

Internal Surface ◽

Building Blocks ◽

Structural Features ◽

Generative Models ◽

Combinatorial Design ◽

Surface Areas ◽

Molecular Building Blocks ◽

Metal Organic

Reticular frameworks are crystalline porous materials that form via the self-assembly of molecular building blocks (i.e., nodes and linkers) in different topologies. Many of them have high internal surface areas and other desirable properties for gas storage, separation, and other applications. The notable variety of the possible building blocks and the diverse ways they can be assembled endow reticular frameworks with a near-infinite combinatorial design space, making reticular chemistry both promising and challenging for prospective materials design. Here, we propose an automated nanoporous materials discovery platform powered by a supramolecular variational autoencoder (SmVAE) for the generative design of reticular materials with desired functions. We demonstrate the automated design process with a class of metal-organic framework (MOF) structures and the goal of separating CO2 from natural gas or flue gas. Our model exhibits high fidelity in capturing structural features and reconstructing MOF structures. We show that the autoencoder has a promising optimization capability when jointly trained with multiple top adsorbent candidates identified for superior gas separation. MOFs discovered here are strongly competitive against some of the best-performing MOFs/zeolites ever reported. This platform lays the groundwork for the design of reticular frameworks for desired applications.

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Interpenetrating metal-organic frameworks formed by self-assembly of tetrahedral and octahedral building blocks

Journal of Solid State Chemistry ◽

10.1016/j.jssc.2009.08.018 ◽

2009 ◽

Vol 182 (11) ◽

pp. 3105-3112 ◽

Cited By ~ 11

Author(s):

Yong-Ming Lu ◽

Ya-Qian Lan ◽

Yan-Hong Xu ◽

Zhong-Min Su ◽

Shun-Li Li ◽

...

Keyword(s):

Self Assembly ◽

Metal Organic Frameworks ◽

Building Blocks ◽

Metal Organic

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Inverse Design of Nanoporous Crystalline Reticular Materials with Deep Generative Models

10.26434/chemrxiv.12186681.v2 ◽

2020 ◽

Author(s):

Zhenpeng Yao ◽

Benjamin Sanchez-Lengeling ◽

N. Scott Bobbitt ◽

Benjamin J. Bucior ◽

Sai Govind Hari Kumar ◽

...

Keyword(s):

Self Assembly ◽

Metal Organic Framework ◽

Internal Surface ◽

Building Blocks ◽

Structural Features ◽

Generative Models ◽

Combinatorial Design ◽

Surface Areas ◽

Molecular Building Blocks ◽

Metal Organic

Reticular frameworks are crystalline porous materials that form via the self-assembly of molecular building blocks (i.e., nodes and linkers) in different topologies. Many of them have high internal surface areas and other desirable properties for gas storage, separation, and other applications. The notable variety of the possible building blocks and the diverse ways they can be assembled endow reticular frameworks with a near-infinite combinatorial design space, making reticular chemistry both promising and challenging for prospective materials design. Here, we propose an automated nanoporous materials discovery platform powered by a supramolecular variational autoencoder (SmVAE) for the generative design of reticular materials with desired functions. We demonstrate the automated design process with a class of metal-organic framework (MOF) structures and the goal of separating CO2 from natural gas or flue gas. Our model exhibits high fidelity in capturing structural features and reconstructing MOF structures. We show that the autoencoder has a promising optimization capability when jointly trained with multiple top adsorbent candidates identified for superior gas separation. MOFs discovered here are strongly competitive against some of the best-performing MOFs/zeolites ever reported. This platform lays the groundwork for the design of reticular frameworks for desired applications.

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Inhibition of the urea-urease reaction by the components of the zeolite imidazole frameworks-8 and the formation of urease-zinc-imidazole hybrid compound

Reaction Kinetics Mechanisms and Catalysis ◽

10.1007/s11144-021-02139-w ◽

2022 ◽

Author(s):

Norbert Német ◽

Ylenia Miele ◽

Gábor Shuszter ◽

Eszter L. Tóth ◽

János Endre Maróti ◽

...

Keyword(s):

Self Assembly ◽

Enzymatic Reaction ◽

Synthesis Method ◽

Material Design ◽

Building Blocks ◽

Zinc Ions ◽

Material Synthesis ◽

Hybrid Compound ◽

Inhibition Effect ◽

Metal Organic

AbstractIn the past decade, much effort has been devoted to using chemical clock-type reactions in material design and driving the self-assembly of various building blocks. Urea-urease enzymatic reaction has chemical pH clock behavior in an unbuffered medium, in which the induction time and the final pH can be programmed by the concentrations of the reagents. The urea-urease reaction can offer a new alternative in material synthesis, where the pH and its course in time are crucial factors in the synthesis. However, before using it in any synthesis method, it is important to investigate the possible effects of the reagents on the enzymatic reaction. Here we investigate the effect of the reagents of the zeolite imidazole framework-8 (zinc ions and 2-methylimidazole) on the urea-urease reaction. We have chosen the zeolite imidazole framework-8 because its formation serves as a model reaction for the formation of other metal–organic frameworks. We found that, besides the inhibition effect of the zinc ions which is well-known in the literature, 2-methylimidazole inhibits the enzymatic reaction as well. In addition to the observed inhibition effect, we report the formation of a hybrid urease-zinc-2-methylimidazole hybrid material. To support the inhibition effect, we developed a kinetic model which reproduced qualitatively the experimentally observed kinetic curves.

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Soft Materials with Diverse Suprastructures via the Self-Assembly of Metal–Organic Complexes

Accounts of Chemical Research ◽

10.1021/acs.accounts.8b00663 ◽

2019 ◽

Vol 52 (3) ◽

pp. 802-817 ◽

Cited By ~ 57

Author(s):

Yan Sun ◽

Chongyi Chen ◽

Peter J. Stang

Keyword(s):

Self Assembly ◽

Soft Materials ◽

The Self ◽

Organic Complexes ◽

Metal Organic

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Spatiotemporal Control of Supramolecular Polymerization and Gelation of Metal-Organic Polyhedra

10.26434/chemrxiv.13414646.v1 ◽

2020 ◽

Author(s):

alexandre legrand ◽

Li-Hao Liu ◽

Philipp Royla ◽

Takuma Aoyama ◽

Gavin Craig ◽

...

Keyword(s):

Acid Concentration ◽

Self Assembly ◽

Colloidal Particles ◽

Soft Materials ◽

Supramolecular Materials ◽

Time Resolved ◽

Colloidal Gel ◽

Metal Organic ◽

Spatiotemporal Control ◽

Gel Network

In coordination-based supramolecular materials such as metallogels, simultaneous temporal and spatial control of their assembly remains challenging. Here, we demonstrate that the combination of light with acids as stimuli allows for the spatiotemporal control over the architectures, mechanical properties, and shape of porous soft materials based on metal-organic polyhedra (MOPs). First, we show that the formation of a colloidal gel network from a preformed kinetically trapped MOP solution can be triggered upon addition of trifluoroacetic acid (TFA), and that acid concentration determines the reaction kinetics. As determined by time-resolved dynamic light scattering, UV-vis absorption and 1H NMR spectroscopies and rheology measurements, the consequences of the increase in acid concentration are (i) an increase in the cross-linking between MOPs; (ii) a growth in the size of the colloidal particles forming the gel network; (iii) an increase in the density of the colloidal network; and (iv) a decrease in the ductility and stiffness of the resulting gel. We then demonstrate that irradiation of a dispersed photoacid generator, pyranine, allows the spatiotemporal control of the gel formation by locally triggering the self-assembly process. Using this methodology, we show that the gel can be patterned into a desired shape. Such precise positioning of the assembled structures, combined with the stable and permanent porosity of MOPs, could allow their integration into devices for applications such as sensing, separation, catalysis, or drug release.

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A bracket approach to improve the stability and gas sorption performance of a metal–organic framework via in situ incorporating the size-matching molecular building blocks

Chemical Communications ◽

10.1039/c6cc02359b ◽

2016 ◽

Vol 52 (54) ◽

pp. 8413-8416 ◽

Cited By ~ 61

Author(s):

Di-Ming Chen ◽

Jia-Yue Tian ◽

Chun-Sen Liu ◽

Miao Du

Keyword(s):

Metal Organic Framework ◽

Building Blocks ◽

Gas Sorption ◽

Molecular Building Blocks ◽

Metal Organic ◽

Coordination Framework ◽

The Stability ◽

Organic Framework

The robustness and gas sorption performance of a coordination framework can be greatly improved by incorporating size-matching molecular building blocks.

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