Controllable Synthesis of Cobalt Porphyrin Nanocrystals through Micelle Confinement Self-Assembly

MRS Advances ◽  
2020 ◽  
Vol 5 (42) ◽  
pp. 2147-2155
Author(s):  
Sudi Chen ◽  
Xitong Ren ◽  
Shufang Tian ◽  
Jiajie Sun ◽  
Feng Bai
Keyword(s):  
Self Assembly ◽  
Water Oxidation ◽  
Separation Efficiency ◽  
Noncovalent Interactions ◽  
Building Blocks ◽  
The Self ◽  
Hexagonal Prism ◽  
Assembly Process ◽  
Surfactant Micelles ◽  
Cobalt Porphyrin

AbstractThe self-assembly of optically active building blocks into functional nanocrystals as high-activity photocatalysts is a key in the field of photocatalysis. Cobalt porphyrin with abundant catalytic properties is extensively studied in photocatalytic water oxidation and CO2 reduction. Here, we present the fabrication of cobalt porphyrin nanocrystals through a surfactant-assisted interfacial self-assembly process using Co-tetra(4-pyridyl) porphyrin as building block. The self-assembly process relies on the combined noncovalent interactions such as π-π stacking and axial Co-N coordination between individual porphyrin molecules within surfactant micelles. Tuning different reaction conditions (temperature, the ratio of co-solvent DMF) and types of surfactant, various nanocrystals with well-defined 1D to 3D morphologies such as nanowires, nanorods and nano hexagonal prism were obtained. Due to the ordered accumulation of molecules, the nanocrystals exhibit the properties of the enhanced capability of visible light capture and can conduce to improve the transport and separation efficiency of the photogenerated carriers, which is important for photocatalysis. Further studies of photocatalytic CO2 reduction are being performed to address the relationship between the size and shape of the nanocrystals with the photocatalytic activity.

scholarly journals Modification of a Single Atom Affects the Physical Properties of Double Fluorinated Fmoc-Phe Derivatives

2021 ◽  
Vol 22 (17) ◽  
pp. 9634
Author(s):  
Moran Aviv ◽  
Dana Cohen-Gerassi ◽  
Asuka A. Orr ◽  
Rajkumar Misra ◽  
Zohar A. Arnon ◽  
...  
Keyword(s):  
Amino Acid ◽  
Physical Properties ◽  
Self Assembly ◽  
Deep Understanding ◽  
Building Blocks ◽  
The Self ◽  
Single Atom ◽  
Supramolecular Organization ◽  
Assembly Process ◽  
Wide Range

Supramolecular hydrogels formed by the self-assembly of amino-acid based gelators are receiving increasing attention from the fields of biomedicine and material science. Self-assembled systems exhibit well-ordered functional architectures and unique physicochemical properties. However, the control over the kinetics and mechanical properties of the end-products remains puzzling. A minimal alteration of the chemical environment could cause a significant impact. In this context, we report the effects of modifying the position of a single atom on the properties and kinetics of the self-assembly process. A combination of experimental and computational methods, used to investigate double-fluorinated Fmoc-Phe derivatives, Fmoc-3,4F-Phe and Fmoc-3,5F-Phe, reveals the unique effects of modifying the position of a single fluorine on the self-assembly process, and the physical properties of the product. The presence of significant physical and morphological differences between the two derivatives was verified by molecular-dynamics simulations. Analysis of the spontaneous phase-transition of both building blocks, as well as crystal X-ray diffraction to determine the molecular structure of Fmoc-3,4F-Phe, are in good agreement with known changes in the Phe fluorination pattern and highlight the effect of a single atom position on the self-assembly process. These findings prove that fluorination is an effective strategy to influence supramolecular organization on the nanoscale. Moreover, we believe that a deep understanding of the self-assembly process may provide fundamental insights that will facilitate the development of optimal amino-acid-based low-molecular-weight hydrogelators for a wide range of applications.

scholarly journals Supramolecular Alloys from Fluorinated Hybrid [4+6] Imine Cages

2021 ◽  
Author(s):  
Tom Kunde ◽  
Tobias Pausch ◽  
Bernd M. Schmidt
Keyword(s):  
Thermal Stability ◽  
Self Assembly ◽  
Gain Control ◽  
Building Blocks ◽  
The Self ◽  
Feed Ratio ◽  
Assembly Process ◽  
Fluorinated Building Blocks ◽  
Efficient Control ◽  
Innovative Materials

To create innovative materials, efficient control and engineering of pore sizes and their characteristics, crystallinity and stability is required. Eight hybrid [4+6] imine cages with a tuneable degree of fluorination and one fully fluorinated [4+6] imine cage are investigated. Although the fluorinated and the non-fluorinated building blocks used herein differ vastly in reactivity, we are able to gain control over the outcome of the self-assembly process, by carefully controlling the feed ratio. This represents the first hybrid material based on fluorinated/hydrogenated porous organic cages (POCs). These alloys with unlimited miscibility in the solid state were obtained as highly crystalline samples after recrystallization and even showed retention of the crystal lattice. All alloys and the fully fluorinated [4+6] imine cage were analysed by MALDI-MS, SCXRD, PXRD and in regards to thermal stability (TGA). <br>

scholarly journals Metallo-organic ensembles of tritopic subphthalocyanine ligands

2017 ◽  
Vol 21 (12) ◽  
pp. 782-789 ◽  
Author(s):  
M. Ángel Revuelta-Maza ◽  
Ettore Fazio ◽  
Gema de la Torre ◽  
Tomás Torres
Keyword(s):  
Mass Spectrometry ◽  
Self Assembly ◽  
Direct Injection ◽  
Building Blocks ◽  
The Self ◽  
Assembly Process ◽  
Text Structures ◽  
Assembly Method ◽  
Injection Techniques

Organic building blocks containing amines and aldehydes can be used for the preparation of complex metallo-organic structures, such as M[Formula: see text]L[Formula: see text] triple helicates or face-capped M[Formula: see text]L[Formula: see text] tetrahedral cages, through the formation of both dynamic covalent and coordinative linkages during the self-assembly process. Herein we describe how the subcomponent self-assembly method can be succesfully applied over a triamine-functionalized subphthalocyanine (SubPc) ligand to build metallo-supramolecular helicates. Two isomeric SubPcs (C[Formula: see text]-SubPc1 and C[Formula: see text]-SubPc1) have been prepared from the corresponding C[Formula: see text]-SubPcI[Formula: see text] and C[Formula: see text]-SubPcI[Formula: see text] precursors under optimized Suzuki conditions. We selected the tritopic C[Formula: see text]-SubPc1 derivative as ligand for the subcomponent self-assembly experiments, which involved the reaction with 2-formylpyridine and different Fe(II) salts. The self-assembly process was mainly studied by mass spectrometry (ESI direct injection techniques), and in all the conditions applied, we could observe the formation of helicate-type Fe[Formula: see text]SubPc[Formula: see text] structures and/or Fe[Formula: see text]SubPc[Formula: see text] species, which can be considered as open precursors of Fe[Formula: see text]SubPc[Formula: see text] tetrahedral cages.

Influence of acidic media on the supramolecular aggregation of iso-tellurazole N-oxides

2016 ◽  
Vol 94 (5) ◽  
pp. 453-457 ◽  
Author(s):  
Peter C. Ho ◽  
Lucia Myongwon Lee ◽  
Hilary Jenkins ◽  
James F. Britten ◽  
Ignacio Vargas-Baca
Keyword(s):  
Oxygen Atom ◽  
Self Assembly ◽  
Building Blocks ◽  
The Self ◽  
Assembly Process ◽  
Acidic Media ◽  
Protonated Molecules ◽  
Supramolecular Aggregation ◽  
Secondary Bonding

Iso-tellurazole N-oxides are promising supramolecular building blocks. While in neutral solutions, they form tetra- and hexameric macrocyclic aggregates linked by Te···O secondary bonding (σ hole interactions or chalcogen bonds), protonation of the oxygen atom in acidic media disrupts such supramolecular association. The process is reversible and, consequently, can be used to switch on and off the self-assembly process. Hammett acidity measurements gave pKa values of –3.2 for the protonated molecules. Adducts with HCl and HBr were isolated and structurally characterized. Protonation in solution led to the crystallization of a new polymorph of 3-methyl-5-phenyl-1,2-tellurazole N-oxide, which features a unique polymeric arrangement.

Influence of the Substitution Position in the Tetratopic Building Blocks on the Self-Assembly Process

2021 ◽  
pp. 117074
Author(s):  
Ł. Baran ◽  
Konrad Dyk ◽  
Daniel Michael Kamiński ◽  
Marek Stankevič ◽  
Wojciech Rżysko ◽  
...  
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
The Self ◽  
Assembly Process

scholarly journals Supramolecular Alloys from Fluorinated Hybrid [4+6] Imine Cages

2021 ◽  
Author(s):  
Tom Kunde ◽  
Tobias Pausch ◽  
Bernd M. Schmidt
Keyword(s):  
Thermal Stability ◽  
Self Assembly ◽  
Gain Control ◽  
Building Blocks ◽  
The Self ◽  
Feed Ratio ◽  
Assembly Process ◽  
Fluorinated Building Blocks ◽  
Efficient Control ◽  
Innovative Materials

To create innovative materials, efficient control and engineering of pore sizes and their characteristics, crystallinity and stability is required. Eight hybrid [4+6] imine cages with a tuneable degree of fluorination and one fully fluorinated [4+6] imine cage are investigated. Although the fluorinated and the non-fluorinated building blocks used herein differ vastly in reactivity, we are able to gain control over the outcome of the self-assembly process, by carefully controlling the feed ratio. This represents the first hybrid material based on fluorinated/hydrogenated porous organic cages (POCs). These alloys with unlimited miscibility in the solid state were obtained as highly crystalline samples after recrystallization and even showed retention of the crystal lattice. All alloys and the fully fluorinated [4+6] imine cage were analysed by MALDI-MS, SCXRD, PXRD and in regards to thermal stability (TGA). <br>

scholarly journals Homochiral Supramolecular Thin Film from Self-Assembly of Achiral Triarylamine Molecules by Circularly Polarized Light

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 402
Author(s):  
Changjun Park ◽  
Jinhee Lee ◽  
Taehyoung Kim ◽  
Jaechang Lim ◽  
Jeyoung Park ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Self Assembly ◽  
Polarized Light ◽  
Building Blocks ◽  
The Self ◽  
Assembly Process ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Self Assembled

Here, we report the formation of homochiral supramolecular thin film from achiral molecules, by using circularly polarized light (CPL) only as a chiral source, on the condition that irradiation of CPL does not induce a photochemical change of the achiral molecules. Thin films of self-assembled structures consisting of chiral supramolecular fibrils was obtained from the triarylamine derivatives through evaporation of the self-assembled triarylamine solution. The homochiral supramolecular helices with the desired handedness was achieved by irradiation of circularly polarized visible light during the self-assembly process, and the chiral stability of supramolecular self-assembled product was achieved by photopolymerization of the diacetylene moieties at side chains of the building blocks, with irradiation of circularly polarized ultraviolet light. This work provides a novel methodology for the generation of homochiral supramolecular thin film from the corresponding achiral molecules.

scholarly journals Self-Assembled Nanomaterials Based on Complementary Sn(IV) and Zn(II)-Porphyrins, and Their Photocatalytic Degradation for Rhodamine B Dye

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3598
Author(s):  
Nirmal K. Shee ◽  
Hee-Joon Kim
Keyword(s):  
Aqueous Solution ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Self Assembly ◽  
The Self ◽  
Assembly Process ◽  
Absorption Bands ◽  
Ligand Coordination ◽  
Rhodamine B Dye ◽  
Metal Ligand

A series of porphyrin triads (1–6), based on the reaction of trans-dihydroxo-[5,15-bis(3-pyridyl)-10,20-bis(phenyl)porphyrinato]tin(IV) (SnP) with six different phenoxy Zn(II)-porphyrins (ZnLn), was synthesized. The cooperative metal–ligand coordination of 3-pyridyl nitrogens in the SnP with the phenoxy Zn(II)-porphyrins, followed by the self-assembly process, leads to the formation of nanostructures. The red-shifts and remarkable broadening of the absorption bands in the UV–vis spectra for the triads in CHCl3 indicate that nanoaggregates may be produced in the self-assembly process of these triads. The emission intensities of the triads were also significantly reduced due to the aggregation. Microscopic analyses of the nanostructures of the triads reveal differences due to the different substituents on the axial Zn(II)-porphyrin moieties. All these nanomaterials exhibited efficient photocatalytic performances in the degradation of rhodamine B (RhB) dye under visible light irradiation, and the degradation efficiencies of RhB in aqueous solution were observed to be 72~95% within 4 h. In addition, the efficiency of the catalyst was not impaired, showing excellent recyclability even after being applied for the degradation of RhB in up to five cycles.

scholarly journals Metal Oxide-Related Dendritic Structures: Self-Assembly and Applications for Sensor, Catalysis, Energy Conversion and Beyond

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1686
Author(s):  
Ruohong Sui ◽  
Paul A. Charpentier ◽  
Robert A. Marriott
Keyword(s):  
Metal Oxide ◽  
Energy Conversion ◽  
Self Assembly ◽  
Hierarchical Structures ◽  
The Self ◽  
Assembly Process ◽  
Electronic Noses ◽  
Dendritic Nanostructures ◽  
Energy Conversion And Storage ◽  
The Aesthetic

In the past two decades, we have learned a great deal about self-assembly of dendritic metal oxide structures, partially inspired by the nanostructures mimicking the aesthetic hierarchical structures of ferns and corals. The self-assembly process involves either anisotropic polycondensation or molecular recognition mechanisms. The major driving force for research in this field is due to the wide variety of applications in addition to the unique structures and properties of these dendritic nanostructures. Our purpose of this minireview is twofold: (1) to showcase what we have learned so far about how the self-assembly process occurs; and (2) to encourage people to use this type of material for drug delivery, renewable energy conversion and storage, biomaterials, and electronic noses.

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