scholarly journals Pyramidal Heteroanion-Directed and Reduced MoV-Driven Assembly of Multi-Layered Polyoxometalate Cages

2018 ◽  
Author(s):  
Qi Zheng, ◽  
Manuel Kupper ◽  
Weimin Xuan ◽  
Hirofumi Oki ◽  
Ryo Tsunashima ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Mixed Valence ◽  
The Self ◽  
Model Structure ◽  
Redox Titration ◽  
Metal Centers ◽  
Redox Active ◽  
Tetrabutyl Ammonium

The fabrication of redox-active polyoxometalates (POMs) that can switch between multiple states is critical for their application in electronic devices, yet, a sophisticated synthetic methodology is not well developed for such cluster types. Here we describe the heteroanion-directed and reduction-driven assembly of a series of multi-layered POM cages 1-10 templated by 1-3 redox-active pyramidal heteroanions. The heteroanions greatly affect the selfassembly of the resultant POM cages, leading to the generation of unprecedented three-layered peanut-shaped - 4, 7 and 8 - or bulletshaped - 5 and 6 - structures. The introduction of reduced molybdate is essential for the self-assembly of the compounds and results in mixed-metal (W/Mo), and mixed-valence (WVI/MoV) 1-10, as confirmed by redox titration, UV-Vis-NIR, NMR spectroscopy and mass spectrometry. 11, the tetrabutyl ammonium (TBA) salt derivative of the fully oxidized 3, is produced as a model structure for measurements to confirm that 1-10 are a statistical mixture of isostructural clusters with different ratios of W/Mo. Finally, multilayered POM cages exhibit dipole relaxations due to the presence of mixed valence WVI/MoV metal centers, demonstrating their potential uses for electronic materials.

scholarly journals Pyramidal Heteroanion-Directed and Reduced MoV-Driven Assembly of Multi-Layered Polyoxometalate Cages

2018 ◽  
Author(s):  
Qi Zheng, ◽  
Manuel Kupper ◽  
Weimin Xuan ◽  
Hirofumi Oki ◽  
Ryo Tsunashima ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Mixed Valence ◽  
The Self ◽  
Model Structure ◽  
Redox Titration ◽  
Metal Centers ◽  
Redox Active ◽  
Tetrabutyl Ammonium

The fabrication of redox-active polyoxometalates (POMs) that can switch between multiple states is critical for their application in electronic devices, yet, a sophisticated synthetic methodology is not well developed for such cluster types. Here we describe the heteroanion-directed and reduction-driven assembly of a series of multi-layered POM cages 1-10 templated by 1-3 redox-active pyramidal heteroanions. The heteroanions greatly affect the selfassembly of the resultant POM cages, leading to the generation of unprecedented three-layered peanut-shaped - 4, 7 and 8 - or bulletshaped - 5 and 6 - structures. The introduction of reduced molybdate is essential for the self-assembly of the compounds and results in mixed-metal (W/Mo), and mixed-valence (WVI/MoV) 1-10, as confirmed by redox titration, UV-Vis-NIR, NMR spectroscopy and mass spectrometry. 11, the tetrabutyl ammonium (TBA) salt derivative of the fully oxidized 3, is produced as a model structure for measurements to confirm that 1-10 are a statistical mixture of isostructural clusters with different ratios of W/Mo. Finally, multilayered POM cages exhibit dipole relaxations due to the presence of mixed valence WVI/MoV metal centers, demonstrating their potential uses for electronic materials.

Comparing the self-assembly processes of two redox-active exTTF-based regioisomer ligands

2021 ◽  
Author(s):  
Maksym DEKHTIARENKO ◽  
Magali Allain ◽  
Vincent Carre ◽  
Frédéric Aubriet ◽  
Zoia Voitenko ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Redox Active

The synthesis of a new tetratopic extended-TTF (exTTF; 9,10-di(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene) ligand, bearing the four pyridyl coordinating functions on the dihydroanthracenyl platform rather than on the 1,3-dithiol rings (previously described regioisomer), is...

The self-assembly of redox active peptides: Synthesis and electrochemical capacitive behavior

Biopolymers ◽  
2016 ◽  
Vol 106 (3) ◽  
pp. 357-367 ◽  
Author(s):  
Julia P. Piccoli ◽  
Adriano Santos ◽  
Norival A. Santos-Filho ◽  
Esteban N. Lorenzón ◽  
Eduardo M. Cilli ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Active Peptides ◽  
Capacitive Behavior ◽  
Redox Active ◽  
Peptides Synthesis

scholarly journals Self-assembled peptide nanostructures for electrical, optical, and magnetic applications

2018 ◽  
Author(s):  
◽  
Soma Khanra
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Nonlinear Optical ◽  
Electronic Devices ◽  
Longitudinal Component ◽  
The Self ◽  
Assembly Process ◽  
Experimental Characterization ◽  
X Ray ◽  
Self Assembled

Bio-nanotechnology has become a widespread exciting field of research as the basic biological structure of bio-inspired materials and nanotechnology share the common length scale. Bio-nanotechnology, which is mainly based on bio-inspired nanostructured materials, has potential applications in nanomedicine, drug delivery, bio-sensors, and bio-degradable electronic devices. The nanostructures obtained from biomolecules are attractive due to their biocompatibility for molecular recognition, ease of chemical modification, and the ability to scaffold other organic and inorganic materials. Peptide nanostructures formed through the self-assembly process of the basic building block of diphenylalanine show promising applications in biodegradable electronic devices, drug delivery, catalysis agent, waveguide, and frequency converter. This research focusses on the self-assembly process in a dipeptide, L, L diphenylalanine (FF) and exploring its electronic, optical, and magnetic properties. The role of solvents in the self-assembly process of FF is explored by combining density functional theory (DFT) along with experimental characterization techniques such as electron microscopy, Raman scattering, and x-ray diffraction (XRD). One of the objectives of this work was to explore the nonlinear optical (NLO) properties of FF nanostructures via second harmonic generation (SHG). The ratio of the nonlinear optical coefficients was obtained from individual FF nanotubes as a function of the tube diameter and thermal annealing conditions. The ratio of the shear to the longitudinal component (d15/d33) of the NLO coefficient increases with the diameter of the tubes. One of the transverse components, d31, of the NLO coefficient is found to be negative, and its magnitude with respect to the longitudinal component (d33) increases with the tube diameter. Thermal treatment of individual FF tubes has a similar effect as increasing the diameter of the tubes in SHG polarimetry. The functionalization of FF micro-nanostructures (FF-MNS) with nanomaterials was studied. FF-MNS with Ag or Au nanoparticles were explored in surface-enhanced Raman scattering (SERS). Such self-assembled nanostructures provide a natural template for tethering Au and Ag nanoparticles (Nps) due to its fractal surface. The FF-MNS undergo an irreversible phase transition from hexagonal packing (hex) to an orthorhombic (ort) structure at [about] 150 [degree]C. The metal Nps form chains on hex FF-MNS as inferred from transmission electron microscopy images and a uniform non-aggregated distribution in the ort phase. The SERS spectra obtained from R6G bound to FF-MNSs with AuNps show a higher enhancement for the ort phase compared with the hex phase. The experimental results agree well with our calculated Raman spectra of model systems using DFT. Our results indicate that FF-MNS both in the hex and ort phase can be used as substrates for SERS analysis with different metal Nps, opening up a novel class of optically active bio-based substrates. The use of magnetic nanoparticles with biomolecules offers a versatile path for tuning the functionality of the composite material for several applications. The functionalization of FF-MNS with cobalt ferrite (CFO) magnetic nanoparticles was achieved. The interaction between CFO nanoparticles and FF-MNS was investigated by optical spectroscopy, x-ray photoelectron spectroscopy (XPS), and magnetization measurements. The changes in the XPS data from pristine FF-MNS and CFO:FF-MNS are indicative of a charge transfer process from CFO to FF-MNS, changing the electronic states of the Fe2+ and Co2+ ions. A comparison of the magnetic characterization from CFO nanoparticles and CFO:FF-MNS shows a higher saturation magnetization from the nanocomposite sample, which is attributed to a change in the cationic distribution in CFO upon binding with the peptide. We were further successful in demonstrating the application of FF-MNS as a bio-degradable active layer in an organic light emitting diode (OLED). FF-MNS were functionalized with two blue-emitting conducting polymers: di-octyl-substituted polyfluorene (PF8) and ethyl-hexyl polyfluorene (PF2/6), and used as an active layer in an OLED architecture. A combination of molecular dynamics and experimental characterization techniques reveals a stronger binding mechanism for PF8 compared to PF2/6 with FF-MNS. Biodegradability tests from FF-MNS:PF8 nanocomposite films show more than 80% weight loss in 2 h by enzymatic action compared to PF8 pristine films, which do not degrade. Self-assembled FF-MNS with organic semiconductors open up a new generation of biocompatible and biodegradable materials in organic electronics.

scholarly journals The role of ligands in coinage-metal nanoparticles for electronics

2017 ◽  
Vol 8 ◽  
pp. 2625-2639 ◽  
Author(s):  
Ioannis Kanelidis ◽  
Tobias Kraus
Keyword(s):  
Metal Nanoparticles ◽  
Self Assembly ◽  
Colloidal Stability ◽  
Chemical Nature ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Coinage Metal ◽  
Conductive Composites ◽  
Particle Shapes

Coinage-metal nanoparticles are key components of many printable electronic inks. They can be combined with polymers to form conductive composites and have been used as the basis of molecular electronic devices. This review summarizes the multidimensional role of surface ligands that cover their metal cores. Ligands not only passivate crystal facets and determine growth rates and shapes; they also affect size and colloidal stability. Particle shapes can be tuned via the ligand choice while ligand length, size, ω-functionalities, and chemical nature influence shelf-life and stability of nanoparticles in dispersions. When particles are deposited, ligands affect the electrical properties of the resulting film, the morphology of particle films, and the nature of the interfaces. The effects of the ligands on sintering, cross-linking, and self-assembly of particles in electronic materials are discussed.

Self-Assembling 2D Nano-Crystalline of Recombinant Surface Layer Proteins (S-Layer) on Solid Substrates and Electrical Responses

MRS Advances ◽  
2017 ◽  
Vol 2 (6) ◽  
pp. 349-355 ◽  
Author(s):  
Rui Qing
Keyword(s):  
Self Assembly ◽  
Electrical Response ◽  
Electronic Devices ◽  
Scale Up ◽  
The Self ◽  
Square Lattice ◽  
Double Layers ◽  
Unit Cell Size ◽  
Self Assembling ◽  
Nano Crystalline

ABSTRACTS-layer proteins of various lattice-forming types are the most abundant protein by mass on earth. They form the outermost cell crystalline component in a broad range of bacteria and archaea. They are porous monomolecular layer with unit cell size in tens of nanometers. These monomer proteins are capable of forming self-assembled mono- or double layers. Isolated from cell surfaces or through recombinant protein production, they are able to form ordered 2D crystal lattice on a variety of non-cellular surfaces. We study S-layer SbpA protein, which is found in mesophilic organism Lysinibacillus sphaericus with square lattice crystallinity. The recombinant SbpA (rSbpA) can be genetically modified and expressed in E. coli in different truncated forms. Using both the wtSpbA and truncated rSbpA, we reproduced the unique two-dimensional self-assembly pattern on several solid or flexible surfaces of interests towards electronic devices. By surface modification we can promote the self-assembly of SbpA on low affinity substrates. This enables a potential mean of creating complex functional bio-nanostructure. Delicate control of the self-assembly processes of S-layer on surfaces also serves the prerequisite of building the supramolecular structure as bio-electronic platform through protein fusing. Understanding of the electrical response from s-layer proteins provides a bridge between biological systems and electronic devices. Scale-up production and understanding the detailed interaction of the S-layer interface will likely be useful for nanobiotechnology and synthetic biology.

ChemInform Abstract: The Self-Assembly of Redox-Active and Photoactive Catenanes and Rotaxanes

ChemInform ◽  
2010 ◽  
Vol 26 (36) ◽  
pp. no-no
Author(s):  
J. A. PREECE ◽  
J. F. STODDART
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Redox Active
Sign in / Sign up

Export Citation Format

Share Document