Internal-Edge-Substituted Coumarin-Fused [6]Helicenes: Asymmetric Synthesis, Structural Features, and Control of Self-Assembly

Phase control in the self-assembly of metal-organic frameworks (MOFs) – materials wherein organic ligands connect metal ions or clusters into network solids with potential porosity – is often a case of trial and error. Judicious control over a number of synthetic variables is required to select for the desired topology and control features such as interpenetration and defectivity, which have significant impact on physical properties and application. Herein, we present a comprehensive investigation of self-assembly in the Fe-biphenyl-4,4'-dicarboxylate system, demonstrating that coordination modulation, the addition of competing ligands into solvothermal syntheses, can reliably tune between the kinetic product, non-interpenetrated MIL-88D(Fe), and the thermodynamic product, two-fold interpenetrated MIL-126(Fe). DFT simulations reveal that correlated disorder of the terminal anions on the metal clusters in the interpentrated phase results in H-bonding between adjacent nets and is the thermodynamic driving force for its formation. Coordination modulation slows self-assembly and therefore selects the thermodynamic product MIL-126(Fe), while offering fine control over defectivity, inducing mesoporosity, but electron microscopy shows the MIL-88D(Fe) phase persists in many samples despite not being evident in diffraction experiments, suggesting its presence accounts for the lower than predicted surface areas reported for samples to date. Interpenetration control is also demonstrated by utilizing the 2,2'-bipyridine-5,5'-dicarboxylate linker; DFT simulations show that it is energetically prohibitive for it to adopt the twisted conformation required to form the interpenetrated phase, and are confirmed by experimental data, although multiple alternative phases are identified due to additional coordination of the Fe cations to the N-donors of the ligand. Finally, we introduce oxidation modulation – the concept of using metal precursors in a different oxidation state to that found in the final MOF – as a further protocol to kinetically control self-assembly. Combining coordination and oxidation modulation allows the synthesis of pristine MIL-126(Fe) with BET surface areas close to the predicted maximum capacity for the first time, suggesting that combining the two may be a powerful methodology for the controlled self-assembly of high-valent MOFs.

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Guided Self-Assembly and Control of Vortices in Ensembles of Active Magnetic Rollers

Langmuir ◽

10.1021/acs.langmuir.9b03023 ◽

2019 ◽

Vol 36 (25) ◽

pp. 6957-6962 ◽

Cited By ~ 3

Author(s):

Gašper Kokot ◽

Andrey Sokolov ◽

Alexey Snezhko

Keyword(s):

Self Assembly ◽

And Control

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Zeolates: A Coordination Chemistry View of Metal-Ligand Bonding in Intrazeolite MOCVD Type Precursors and Semiconductor Nanoclusters

MRS Proceedings ◽

10.1557/proc-277-105 ◽

1992 ◽

Vol 277 ◽

Cited By ~ 6

Author(s):

Geoffrey A. Ozin ◽

Carol L. Bowes ◽

Mark R. Steele

Keyword(s):

Self Assembly ◽

Materials Science ◽

Zeolite Y ◽

Chemical Vapour ◽

Internal Surface ◽

Building Blocks ◽

Structural Features ◽

Organic Chemical ◽

Wide Range ◽

Shape Selective

ABSTRACTVarious MOCVD (metal-organic chemical vapour deposition) type precursors and their self-assembled semiconductor nanocluster products [1] have been investigated in zeolite Y hosts. From analysis of in situ observations (FTIR, UV-vis reflectance, Mössbauer, MAS-NMR) of the reaction sequences and structural features of the precursors and products (EXAFS and Rietveld refinement of powder XRD data) the zeolite is viewed as providing a macrospheroidal, multidendate coordination environment towards encapsulated guests. By thinking about the α- and β-cages of the zeolite Y host effectively as a zeolate ligand composed of interconnected aluminosilicate “crown ether-like” building blocks, the materials chemist is able to better understand and exploit the reactivity and coordination properties of the zeolite internal surface for the anchoring and self-assembly of a wide range of encapsulated guests. This approach helps with the design of synthetic strategies for creating novel guest-host inclusion compounds having possible applications in areas of materials science such as nonlinear optics, quantum electronics, and size/shape selective catalysis.

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Research on the Pose Detection and Control Methods of Robot with Series-Parallel Structure

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.303-306.1685 ◽

2013 ◽

Vol 303-306 ◽

pp. 1685-1690 ◽

Cited By ~ 1

Author(s):

Dong Yang ◽

Tie Jun Li ◽

Jin Yue Liu ◽

Hai Wen Zhao

Keyword(s):

Structural Features ◽

Hybrid Structure ◽

Parallel Structure ◽

Sensing Systems ◽

Position Detection ◽

Pose Detection ◽

Building Environment ◽

Automated Installation ◽

And Control ◽

Structured Light Vision

Aiming at the load requirements, positioning accuracy and workflow of building panels installed robot, developed a 6 DOF of a series-parallel hybrid structure installed robot. According to the structural features of parallel mechanism to the installation manipulator, designed a robot attitude sensing system based on the inclination and laser ranging sensor information feedback; according to the characteristics of the building environment, proposed the position detection method of panels to be installed based on the structured light vision; constructed the control system of the installation manipulator, and used teaching mode to achieve robot control and system calibration. The experimental data prove that, the control and sensing systems of panels installed robot, overcome the complexity of the building environment and the diversity of installation object, and can achieve the automated installation of building panels.

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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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Silk Self-Assembly Mechanisms and Control From Thermodynamics to Kinetics

Biomacromolecules ◽

10.1021/bm201731e ◽

2012 ◽

Vol 13 (3) ◽

pp. 826-832 ◽

Cited By ~ 129

Author(s):

Qiang Lu ◽

Hesun Zhu ◽

Cencen Zhang ◽

Feng Zhang ◽

Bing Zhang ◽

...

Keyword(s):

Self Assembly ◽

And Control

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Structure and Self-Assembly of Multicolored Naphthalene Diimides Semiconductor

Nano LIFE ◽

10.1142/s1793984416420071 ◽

2016 ◽

Vol 06 (03n04) ◽

pp. 1642007

Author(s):

Zhili Yao ◽

Yuan Sun ◽

Chen Kang

Keyword(s):

Self Assembly ◽

Optoelectronic Devices ◽

Supramolecular Interactions ◽

Promising Candidate ◽

One Dimensional ◽

Ordered Nanostructures ◽

The One ◽

Naphthalene Diimides ◽

And Control ◽

New Strategies

The one-dimensional (1D) self-assembly of [Formula: see text]-electron molecules offers efficient strategies to enhance energy and charge transfer via highly ordered and conductive [Formula: see text] stacking of the chromophores. The chromophore rich nanostructures have great potential to serve as promising candidate materials for optoelectronic devices. However, the design and control of highly ordered nanostructures with multicolored chromophore redox gradients require finely chosen synthetic strategies and a delicate balance of supramolecular interactions. In this paper, we will introduce new strategies focused on self-assembly of nanofibers based on lysine derivatives functionalized with multi colored chromophores.

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A Novel Pectic Polysaccharide of Jujube Pomace: Structural Analysis and Intracellular Antioxidant Activities

Antioxidants ◽

10.3390/antiox9020127 ◽

2020 ◽

Vol 9 (2) ◽

pp. 127

Author(s):

Ximeng Lin ◽

Keshan Liu ◽

Sheng Yin ◽

Yimin Qin ◽

Peili Shen ◽

...

Keyword(s):

Self Assembly ◽

Antioxidant Activities ◽

Structural Features ◽

Water Retention Capacity ◽

Side Chains ◽

Sem Images ◽

Retention Capacity ◽

Pectic Polysaccharide ◽

Afm Analysis ◽

Fast Flow

After extraction from jujube pomace and purification by two columns (DEAE-Sepharose Fast Flow and Sepharcyl S-300), the structure of SAZMP4 was investigated by HPGPC, GC, FI-IR, GC-MS, NMR, SEM, and AFM. Analysis determined that SAZMP4 (Mw = 28.94 kDa) was a pectic polysaccharide mainly containing 1,4-linked GalA (93.48%) with side chains of 1,2,4-linked Rha and 1,3,5-linked Ara and terminals of 1-linked Rha and 1-linked Ara, which might be the homogalacturonan (HG) type with side chains of the RG-I type, corresponding to the results of NMR. In AFM and SEM images, self-assembly and aggregation of SAZMP4 were respectively observed indicating its structural features. The antioxidant activity of SAZMP4 against H2O2-induced oxidative stress in Caco-2 cells was determined by activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as malondialdehyde (MDA) and reactive oxygen species (ROS) levels, indicating SAZMP4 can be a natural antioxidant. Also, a better water retention capacity and thermal stability of SAZMP4 was observed based on DSC analysis, which could be applied in food industry as an additive.

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Readout and control of an endofullerene electronic spin

Nature Communications ◽

10.1038/s41467-020-20202-3 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Dinesh Pinto ◽

Domenico Paone ◽

Bastian Kern ◽

Tim Dierker ◽

René Wieczorek ◽

...

Keyword(s):

Self Assembly ◽

Large Scale ◽

Dipolar Interaction ◽

Nitrogen Vacancy ◽

Zero Field ◽

Zero Field Splitting ◽

Paramagnetic Resonance ◽

Near Surface ◽

Atomic Spins ◽

And Control

AbstractAtomic spins for quantum technologies need to be individually addressed and positioned with nanoscale precision. C60 fullerene cages offer a robust packaging for atomic spins, while allowing in-situ physical positioning at the nanoscale. However, achieving single-spin level readout and control of endofullerenes has so far remained elusive. In this work, we demonstrate electron paramagnetic resonance on an encapsulated nitrogen spin (14N@C60) within a C60 matrix using a single near-surface nitrogen vacancy (NV) center in diamond at 4.7 K. Exploiting the strong magnetic dipolar interaction between the NV and endofullerene electronic spins, we demonstrate radio-frequency pulse controlled Rabi oscillations and measure spin-echos on an encapsulated spin. Modeling the results using second-order perturbation theory reveals an enhanced hyperfine interaction and zero-field splitting, possibly caused by surface adsorption on diamond. These results demonstrate the first step towards controlling single endofullerenes, and possibly building large-scale endofullerene quantum machines, which can be scaled using standard positioning or self-assembly methods.

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