Tunable longitudinal modes in extended silver nanoparticle assemblies

Nanostructured materials with tunable properties are of great interest for a wide range of applications. The self-assembly of simple nanoparticle building blocks could provide an inexpensive means to achieve this goal. Here, we generate extended anisotropic silver nanoparticle assemblies in solution using controlled amounts of one of three inexpensive, widely available, and environmentally benign short ditopic ligands: cysteamine, dithiothreitol and cysteine in aqueous solution. The self-assembly of our extended structures is enforced by hydrogen bonding. Varying the ligand concentration modulates the extent and density of these unprecedented anisotropic structures. Our results show a correlation between the chain nature of the assembly and the generation of spectral anisotropy. Deuterating the ligand further enhances the anisotropic signal by triggering more compact aggregates and reveals the importance of solvent interactions in assembly size and morphology. Spectral and morphological evolutions of the AgNPs assemblies are followed via UV–visible spectroscopy and transmission electron microscopy (TEM). Spectroscopic measurements are compared to calculations of the absorption spectra of randomly assembled silver chains and aggregates based on the discrete dipole approximation. The models support the experimental findings and reveal the importance of aggregate size and shape as well as particle polarizability in the plasmon coupling between nanoparticles.

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

International Journal of Molecular Sciences ◽

10.3390/ijms22179634 ◽

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.

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The Self-Assembly and Design of Polyfunctional Nanosystems

International Journal of Molecular Sciences ◽

10.3390/ijms22042223 ◽

2021 ◽

Vol 22 (4) ◽

pp. 2223

Author(s):

Ruslan Kashapov ◽

Lucia Zakharova

Keyword(s):

Sustainable Development ◽

Nanostructured Materials ◽

Self Assembly ◽

Building Blocks ◽

The Self ◽

Special Issue ◽

Molecular Building Blocks ◽

Wide Range ◽

Scientific Papers ◽

Current Task

The current task of the molecular sciences is to create unique nanostructured materials with a given structure and with specific physicochemical properties on the basis of the existing wide range of molecules of natural and synthetic origin. A promising and inexpensive way to obtain nanostructured materials is the spontaneous self-assembly of molecular building blocks during random collisions in real dispersive systems in solution and at interfaces. This editorial aims to summarize the major points from the 11 scientific papers that contributed to the special issue “The Self-Assembly and Design of Polyfunctional Nanosystems”, assessing the modern self-assembly potential and strategies for maintaining sustainable development of the nanoindustry.

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Factors Affecting Molecular Self-Assembly and Its Mechanism

Scientific Research Journal ◽

10.24191/srj.v9i1.5385 ◽

2012 ◽

Vol 9 (1) ◽

pp. 43 ◽

Cited By ~ 1

Author(s):

Hueyling Tan

Keyword(s):

Self Assembly ◽

Building Blocks ◽

Molecular Engineering ◽

Molecular Structures ◽

Polymer Science ◽

New Approach ◽

Factors Affecting ◽

Dna Structures ◽

Self Assembling ◽

Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

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Self-Assembly of Shape-Tunable Oblate Colloidal Particles into Orientationally Ordered Crystals, Glassy Crystals and Plastic Crystals

Soft Matter ◽

10.1039/d1sm00343g ◽

2021 ◽

Author(s):

Jiawei Lu ◽

Xiangyu Bu ◽

Xinghua Zhang ◽

Bing Liu

Keyword(s):

Crystal Structures ◽

Self Assembly ◽

Colloidal Particles ◽

Building Blocks ◽

Fundamental Question ◽

The Self ◽

Plastic Crystals ◽

Self Assembled ◽

Glassy Crystals ◽

The Relationship

The shapes of colloidal particles are crucial to the self-assembled superstructures. Understanding the relationship between the shapes of building blocks and the resulting crystal structures is an important fundamental question....

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

MRS Advances ◽

10.1557/adv.2020.269 ◽

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.

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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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A Structurally Variable Hinged Tetrahedron Framework from DNA Origami

Journal of Nucleic Acids ◽

10.4061/2011/360954 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 18

Author(s):

David M. Smith ◽

Verena Schüller ◽

Carsten Forthmann ◽

Robert Schreiber ◽

Philip Tinnefeld ◽

...

Keyword(s):

Self Assembly ◽

Gel Electrophoresis ◽

Imaging Techniques ◽

Building Blocks ◽

Dna Origami ◽

Microscopy Technique ◽

Wire Frame ◽

Wide Range ◽

Potential Applications ◽

Linker Molecules

Nanometer-sized polyhedral wire-frame objects hold a wide range of potential applications both as structural scaffolds as well as a basis for synthetic nanocontainers. The utilization of DNA as basic building blocks for such structures allows the exploitation of bottom-up self-assembly in order to achieve molecular programmability through the pairing of complementary bases. In this work, we report on a hollow but rigid tetrahedron framework of 75 nm strut length constructed with the DNA origami method. Flexible hinges at each of their four joints provide a means for structural variability of the object. Through the opening of gaps along the struts, four variants can be created as confirmed by both gel electrophoresis and direct imaging techniques. The intrinsic site addressability provided by this technique allows the unique targeted attachment of dye and/or linker molecules at any point on the structure's surface, which we prove through the superresolution fluorescence microscopy technique DNA PAINT.

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A Dynamic Route to Structure and Function: Recent Advances in Imine-Based Organic Nanostructured Materials

Australian Journal of Chemistry ◽

10.1071/ch12349 ◽

2013 ◽

Vol 66 (1) ◽

pp. 9 ◽

Cited By ~ 26

Author(s):

Yi Liu ◽

Zhan-Ting Li

Keyword(s):

Self Assembly ◽

Reaction System ◽

Functional Materials ◽

Building Blocks ◽

The Self ◽

Interlocked Molecules ◽

Functional Aspects ◽

Imine Bond ◽

And Function ◽

Dynamic Route

The chemistry of imine bond formation from simple aldehyde and amine precursors is among the most powerful dynamic covalent chemistries employed for the construction of discrete molecular objects and extended molecular frameworks. The reversible nature of the C=N bond confers error-checking and proof-reading capabilities in the self-assembly process within a multi-component reaction system. This review highlights recent progress in the self-assembly of complex organic molecular architectures that are enabled by dynamic imine chemistry, including molecular containers with defined geometry and size, mechanically interlocked molecules, and extended frameworks and polymers, from building blocks with preprogrammed steric and electronic information. The functional aspects associated with the nanometer-scale features not only place these dynamically constructed nanostructures at the frontier of materials sciences, but also bring unprecedented opportunities for the discovery of new functional materials.

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