scholarly journals STM study on the self-assembly of oligothiophene-based organic semiconductors

2011 ◽  
Vol 2 ◽  
pp. 802-808 ◽  
Author(s):  
Elena Mena-Osteritz ◽  
Marta Urdanpilleta ◽  
Erwaa El-Hosseiny ◽  
Berndt Koslowski ◽  
Paul Ziemann ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Self Assembly ◽  
Theoretical Calculations ◽  
The Self ◽  
Scanning Tunneling ◽  
Ambient Conditions ◽  
Tunneling Microscopy ◽  
Substitution Pattern ◽  
Electronic Density ◽  
The Individual

The self-assembly properties of a series of functionalized regioregular oligo(3-alkylthiophenes) were investigated by using scanning tunneling microscopy (STM) at the liquid–solid interface under ambient conditions. The characteristics of the 2-D crystals formed on the (0001) plane of highly ordered pyrolitic graphite (HOPG) strongly depend on the length of the π-conjugated oligomer backbone, on the functional groups attached to it, and on the alkyl substitution pattern on the individual thiophene units. Theoretical calculations were performed to analyze the geometry and electronic density of the molecular orbitals as well as to analyze the intermolecular interactions, in order to obtain models of the 2-D molecular ordering on the substrate.

scholarly journals Halogen Bonds Fabricate 2D Molecular Self-Assembled Nanostructures by Scanning Tunneling Microscopy

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1057
Author(s):  
Yi Wang ◽  
Xinrui Miao ◽  
Wenli Deng
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
Density Functional ◽  
Deep Understanding ◽  
Halogen Bonding ◽  
The Self ◽  
Scanning Tunneling ◽  
Halogen Bonds ◽  
Tunneling Microscopy ◽  
Self Assembled

Halogen bonds are currently new noncovalent interactions due to their moderate strength and high directionality, which are widely investigated in crystal engineering. The study about supramolecular two-dimensional architectures on solid surfaces fabricated by halogen bonding has been performed recently. Scanning tunneling microscopy (STM) has the advantages of realizing in situ, real-time, and atomic-level characterization. Our group has carried out molecular self-assembly induced by halogen bonds at the liquid–solid interface for about ten years. In this review, we mainly describe the concept and history of halogen bonding and the progress in the self-assembly of halogen-based organic molecules at the liquid/graphite interface in our laboratory. Our focus is mainly on (1) the effect of position, number, and type of halogen substituent on the formation of nanostructures; (2) the competition and cooperation of the halogen bond and the hydrogen bond; (3) solution concentration and solvent effects on the molecular assembly; and (4) a deep understanding of the self-assembled mechanism by density functional theory (DFT) calculations.

Scanning Tunneling Microscopy Reveals Single-Molecule Insights into the Self-Assembly of Amyloid Fibrils

ACS Nano ◽  
2012 ◽  
Vol 6 (8) ◽  
pp. 6882-6889 ◽  
Author(s):  
Nataliya Kalashnyk ◽  
Jakob T. Nielsen ◽  
Erik H. Nielsen ◽  
Troels Skrydstrup ◽  
Daniel E. Otzen ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Single Molecule ◽  
Self Assembly ◽  
Amyloid Fibrils ◽  
The Self ◽  
Scanning Tunneling ◽  
Tunneling Microscopy

scholarly journals Potential Driven Non-Reactive Phase Transitions of Ordered Porphyrin Molecules on Iodine-Modified Au(100): An Electrochemical Scanning Tunneling Microscopy (EC-STM) Study

Surfaces ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 12-28 ◽  
Author(s):  
Tomasz Kosmala ◽  
Matías Blanco ◽  
Gaetano Granozzi ◽  
Klaus Wandelt
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Long Range ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
The Self ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Electrode Potentials ◽  
Electrochemical Scanning Tunneling Microscopy

The modelling of long-range ordered nanostructures is still a major issue for the scientific community. In this work, the self-assembly of redox-active tetra(N-methyl-4-pyridyl)-porphyrin cations (H2TMPyP) on an iodine-modified Au(100) electrode surface has been studied by means of Cyclic Voltammetry (CV) and in-situ Electrochemical Scanning Tunneling Microscopy (EC-STM) with submolecular resolution. While the CV measurements enable conclusions about the charge state of the organic species, in particular, the potentio-dynamic in situ STM results provide new insights into the self-assembly phenomena at the solid-liquid interface. In this work, we concentrate on the regime of positive electrode potentials in which the adsorbed molecules are not reduced yet. In this potential regime, the spontaneous adsorption of the H2TMPyP molecules on the anion precovered surface yields the formation of up to five different potential-dependent long-range ordered porphyrin phases. Potentio-dynamic STM measurements, as a function of the applied electrode potential, show that the existing ordered phases are the result of a combination of van der Waals and electrostatic interactions.

Investigation of the non-covalent interactions of molecular self-assembly by scanning tunneling microscopy using the association of aromatic structures in pyrene-4,5,9,10-tetraone and phenanthrene-9,10-dione molecules

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103316-103320 ◽  
Author(s):  
Huiling Zhao ◽  
Shuai Zhang ◽  
Shuang Li ◽  
Xin Song ◽  
Wei Liu ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Aromatic Molecules ◽  
Assembled Monolayers ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The self-assembled monolayers of aromatic molecules (pyrene-4,5,9,10-tetraone and phenanthrene-9,10-dione) were investigated at the liquid/solid (1-phenyloctane/graphite) interface using scanning tunneling microscopy, respectively.

scholarly journals Structural and Nanotribological Properties of a BODIPY Self-Assembly

2021 ◽  
Vol 9 ◽  
Author(s):  
Shanchao Tan ◽  
Wendi Luo ◽  
Yongjie Zhang ◽  
Xiang-Kui Ren ◽  
Yuhong Liu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Density Functional ◽  
Supramolecular Assembly ◽  
Dft Method ◽  
The Self ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Assembly Mechanism

Boron-dipyrromethenes (BODIPY) are promising functional dyes, whose exceptional optical properties are closely related to their supramolecular assembly. Herein, the self-assembly of a BODIPY derivative functionalized with uracil groups is explicitly and thoroughly investigated by using scanning tunneling microscopy (STM). Based on the simulation and calculation by density functional theory (DFT) method, it can be concluded that the construction of ordered self-assembly structure is attributed to the formation of hydrogen bonds between uracil groups. Moreover, the nanotribological property of the self-assembly on HOPG surface is measured by using atomic force microscopy (AFM). The effort on self-assembly of the BODIPY derivative could enhance the understanding of surface assembly mechanism.

scholarly journals Growth of a self-assembled monolayer decoupled from the substrate: nucleation on-command using buffer layers

2020 ◽  
Vol 11 ◽  
pp. 1291-1302
Author(s):  
Robby Reynaerts ◽  
Kunal S Mali ◽  
Steven De Feyter
Keyword(s):  
Buffer Layer ◽  
Self Assembly ◽  
Network Formation ◽  
The Self ◽  
Buffer Layers ◽  
Scanning Tunneling ◽  
Structural Polymorphism ◽  
Tunneling Microscopy ◽  
Self Assembled Monolayer ◽  
Self Assembled

Structural polymorphism is ubiquitous in physisorbed self-assembled monolayers formed at the solution–solid interface. One of the ways to influence network formation at this interface is to physically decouple the self-assembled monolayer from the underlying substrate thereby removing the influence of the substrate lattice, if any. Here we show a systematic exploration of self-assembly of a typical building block, namely 4-tetradecyloxybenzoic acid at the 1-phenyloctane–graphite interface in the presence and in the absence of a buffer layer formed by a long chain alkane, namely n-pentacontane. Using scanning tunneling microscopy (STM), three different structural polymorphs were identified for 4-tetradecyloxybenzoic acid at the 1-phenyloctane–graphite interface. Surprisingly, the same three structures were formed on top of the buffer layer, albeit at different concentrations. Systematic variation of experimental parameters did not lead to any new network in the presence of the buffer layer. We discovered that the self-assembly on top of the buffer layer allows better control over the nanoscale manipulation of the self-assembled networks. Using the influence of the STM tip, we could initiate the nucleation of small isolated domains of the benzoic acid on-command in a reproducible fashion. Such controlled nucleation experiments hold promise for studying fundamental processes inherent to the assembly process on surfaces.

scholarly journals Insight Into the Superlubricity and Self-Assembly of Liquid Crystals

2021 ◽  
Vol 9 ◽  
Author(s):  
Shanchao Tan ◽  
Jiayu Tao ◽  
Wendi Luo ◽  
Hongyu Shi ◽  
Bin Tu ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Self Assembly ◽  
Density Functional ◽  
Pyrolytic Graphite ◽  
Interaction Strength ◽  
Dft Method ◽  
The Self ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Friction Coefficients

Liquid crystals are promising molecular materials in the application of lubrication. Herein, the microscale solid superlubricity is accomplished by the construction of uniform and ordered self-assembly of several liquid crystals. The self-assembly structures on a highly oriented pyrolytic graphite (HOPG) surface are explicitly revealed by using scanning tunneling microscopy (STM). Meanwhile, the nanotribological performance of the self-assemblies are measured by using atomic force microscopy (AFM), revealing ultralow friction coefficients lower than 0.01. The interaction energies are calculated by density functional theory (DFT) method, indicating the positive correlation between friction coefficients and interaction strength. The effort on the self-assembly and superlubricity of liquid crystals could enhance the understanding of the nanotribological mechanism and benefit the further application of liquid crystals as lubricants.

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