scholarly journals Septipyridines as conformationally controlled substitutes for inaccessible bis(terpyridine)-derived oligopyridines in two-dimensional self-assembly

2011 ◽  
Vol 2 ◽  
pp. 405-415 ◽  
Author(s):  
Daniel Caterbow ◽  
Daniela Künzel ◽  
Michael G Mavros ◽  
Axel Groß ◽  
Katharina Landfester ◽  
...  
Keyword(s):  
Self Assembly ◽  
Pyrolytic Graphite ◽  
Scanning Tunneling ◽  
Strong Impact ◽  
Tunneling Microscopy ◽  
New Class ◽  
Self Assembling ◽  
Assembly Behavior ◽  
Structure Calculations ◽  
Transoid Conformation

The position of the peripheral nitrogen atoms in bis(terpyridine)-derived oligopyridines (BTPs) has a strong impact on their self-assembly behavior at the liquid/HOPG (highly oriented pyrolytic graphite) interface. The intermolecular hydrogen bonding interactions in these peripheral pyridine units show specific 2D structures for each BTP isomer. From nine possible constitutional isomers only four have been described in the literature. The synthesis and self-assembling behavior of an additional isomer is presented here, but the remaining four members of the series are synthetically inaccessible. The self-assembling properties of three of the missing four BTP isomers can be mimicked by making use of the energetically preferred N–C–C–N transoid conformation between 2,2'-bipyridine subunits in a new class of so-called septipyridines. The structures are investigated by scanning tunneling microscopy (STM) and a combination of force-field and first-principles electronic structure calculations.

scholarly journals Advanced opto-electronics materials by fullerene and acetylene scaffolding

2005 ◽  
Vol 77 (11) ◽  
pp. 1851-1863 ◽  
Author(s):  
François Diederich
Keyword(s):  
Electronic Properties ◽  
Self Assembly ◽  
Weak Interactions ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Conjugated Systems ◽  
New Class ◽  
Polydisperse Polymer ◽  
Fundamental Research ◽  
Storage Properties

Functional π-systems with unusual opto-electronic properties are intensively investigated from both fundamental research and technological application viewpoints. This article reports on novel π-conjugated systems obtained by acetylenic and fullerene scaffolding. Linearly conjugated acetylenic nanorods, consisting of monodisperse poly(triacetylene) (PTA) oligomers and extending up to 18 nm length, were prepared to investigate the limits of effective conjugation and to explore at which length a monodisperse oligomer reaches the properties of an infinite polydisperse polymer. With the cyanoethynylethenes (CEEs), a powerful new class of electron acceptors is introduced that undergo intense intramolecular charge-transfer (CT) interactions with appended donors. Macrocyclic scaffolds with unusual opto-electronic properties are perethynylated dehydroannulenes, expanded radialenes, and radiaannulenes bearing peripheral dialkylanilino donor groups. Extended porphyrin-fullerene conjugates are investigated for their novel photophysical and efficient multicharge storage properties. Self-assembly of fullerenes and porphyrins, governed by weak interactions between the two components, leads to unprecedented nanopatterned surfaces that are investigated by scanning tunneling microscopy (STM).

Self-Assembly of a Novel Cationic Porphyrin-Anthraquione Hybrid Investigated by Scanning Tunneling Microscopy

2010 ◽  
Vol 148-149 ◽  
pp. 1273-1276 ◽  
Author(s):  
Ai Mei Gao ◽  
Wen Li Deng ◽  
Hong Yu Chen
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Self Assembly ◽  
Large Scale ◽  
Room Temperature ◽  
Pyrolytic Graphite ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Hybrid Compound ◽  
Cationic Porphyrin ◽  
Stm Images

The self-assembly behaviour of a novel cationic porphyrin-anthraquione (Por-AQ) hybrid ([AQATMPyP]I3) on highly oriented pyrolytic graphite (HOPG) was studied at room temperature in air by scanning tunneling microscopy(STM). According to theoretical calculation, it is testified that [AQATMPyP]I3 molecule mainly exists in the closed structure. The STM results reveal the presence of large-scale domains of ordered adlayer of this hybrid compound on HOPG. The STM images show a structure constituted by parallel rows. The width of each row is approximately 2.5nm.

Cooperating dipole–dipole and van der Waals interactions driven 2D self-assembly of fluorenone derivatives: ester chain length effect

2017 ◽  
Vol 19 (46) ◽  
pp. 31113-31120 ◽  
Author(s):  
Meiqiu Dong ◽  
Kai Miao ◽  
Yi Hu ◽  
Juntian Wu ◽  
Jinxing Li ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Chain Length ◽  
Self Assembly ◽  
Pyrolytic Graphite ◽  
Van Der Waals Interactions ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Tunneling Microscopy ◽  
Length Effect ◽  
Ester Chain

Two-dimensional supramolecular assemblies of a series of 2,7-bis(10-n-alkoxycarbonyl-decyloxy)-9-fluorenone derivatives (BAF-Cn, n = 1, 3–6) consisting of polar fluorenone moieties and ester alkoxy chains were investigated by scanning tunneling microscopy on highly oriented pyrolytic graphite 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.

A Bottom-Up Approach to Solution-Processed, Atomically Precise Graphitic Cylinders on Surfaces

2018 ◽  
Author(s):  
Erik Leonhardt ◽  
Jeff M. Van Raden ◽  
David Miller ◽  
Lev N. Zakharov ◽  
Benjamin Aleman ◽  
...  
Keyword(s):  
Self Assembly ◽  
Carbon Nanostructures ◽  
Carbon Nanomaterials ◽  
Circle Packing ◽  
Pyrolytic Graphite ◽  
Building Blocks ◽  
Bottom Up ◽  
Casting Technique ◽  
New Class ◽  
Solution Casting Technique

Extended carbon nanostructures, such as carbon nanotubes (CNTs), exhibit remarkable properties but are difficult to synthesize uniformly. Herein, we present a new class of carbon nanomaterials constructed via the bottom-up self-assembly of cylindrical, atomically-precise small molecules. Guided by supramolecular design principles and circle packing theory, we have designed and synthesized a fluorinated nanohoop that, in the solid-state, self-assembles into nanotube-like arrays with channel diameters of precisely 1.63 nm. A mild solution-casting technique is then used to construct vertical “forests” of these arrays on a highly-ordered pyrolytic graphite (HOPG) surface through epitaxial growth. Furthermore, we show that a basic property of nanohoops, fluorescence, is readily transferred to the bulk phase, implying that the properties of these materials can be directly altered via precise functionalization of their nanohoop building blocks. The strategy presented is expected to have broader applications in the development of new graphitic nanomaterials with π-rich cavities reminiscent of CNTs.

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