Preparation of Azobenzenealkanethiols for Self-Assembled Monolayers with Photoswitchable Properties

2010 ◽  
Vol 63 (2) ◽  
pp. 303 ◽  
Author(s):  
Simone Krakert ◽  
Andreas Terfort
Keyword(s):  
Oxygen Atom ◽  
Hybrid Systems ◽  
Self Assembly ◽  
Alkyl Chain ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Methylene Groups ◽  
Broad Variety ◽  
Fast Access

A series of azobenzenealkanethiol compounds with the structure p-RC6H4N=NC6H4(CH2)nSH (n = 3, 4) was synthesized using a divergent strategy with the two anilines H2NC6H4(CH2)nSAc as central compounds. This strategy provides fast access to a broad variety of the respective azobenzenethiols without (note!) an oxygen atom in the alkyl chain, thus permitting the self-assembly of these compounds onto gold in a predictable conformation, also taking advantage of the previously found odd–even effect in aromatic–aliphatic hybrid systems. Initial experiments indicate that all of these molecules indeed form dense monolayers, in which the orientation of the azobenzene unit is determined by the number of methylene groups in the aliphatic part of the molecules.

scholarly journals STM visualisation of counterions and the effect of charges on self-assembled monolayers of macrocycles

2011 ◽  
Vol 2 ◽  
pp. 674-680 ◽  
Author(s):  
Tibor Kudernac ◽  
Natalia Shabelina ◽  
Wael Mamdouh ◽  
Sigurd Höger ◽  
Steven De Feyter
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Assembly Process ◽  
Organic Monolayers ◽  
Preferential Adsorption ◽  
Scanning Tunnelling ◽  
Assembled Monolayers ◽  
Tunnelling Microscopy ◽  
Self Assembled

Despite their importance in self-assembly processes, the influence of charged counterions on the geometry of self-assembled organic monolayers and their direct localisation within the monolayers has been given little attention. Recently, various examples of self-assembled monolayers composed of charged molecules on surfaces have been reported, but no effort has been made to prove the presence of counterions within the monolayer. Here we show that visualisation and exact localisation of counterions within self-assembled monolayers can be achieved with scanning tunnelling microscopy (STM). The presence of charges on the studied shape-persistent macrocycles is shown to have a profound effect on the self-assembly process at the liquid–solid interface. Furthermore, preferential adsorption was observed for the uncharged analogue of the macrocycle on a surface.

scholarly journals Energy landscapes and dynamics of glycine on Cu(110)

2017 ◽  
Vol 19 (25) ◽  
pp. 16600-16605 ◽  
Author(s):  
Marco Sacchi ◽  
David J. Wales ◽  
Stephen J. Jenkins
Keyword(s):  
Amino Acids ◽  
Single Crystal ◽  
Long Range ◽  
Self Assembly ◽  
Metal Surfaces ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Energy Landscapes ◽  
Assembly Mechanism ◽  
Assembled Monolayers

Amino acids adsorbed on single-crystal metal surfaces have emerged as prototypical systems for exploring the properties that govern the development of long-range chirality in self-assembled monolayers and supramolecular 2D networks. In this study, we characterise the self-assembly mechanism for glycine on the Cu(110) surface.

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.

Scrolling up graphene oxide nanosheets assisted by self-assembled monolayers of alkanethiols

Nanoscale ◽  
2017 ◽  
Vol 9 (28) ◽  
pp. 9997-10001 ◽  
Author(s):  
Lin Wang ◽  
Peng Yang ◽  
Yang Liu ◽  
Xiangru Fang ◽  
Xiaotong Shi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Gold Substrate ◽  
Graphene Oxide Nanosheets ◽  
High Quality ◽  
Humidity Sensing ◽  
Assembled Monolayers ◽  
Self Assembled

The fabrication of high-quality nanoscrolls of GO on a gold substrate assisted by the self-assembly of alkanethiol monolayers for humidity sensing.

A BCC Superlattice of Passivated Gold Nanocrystals

1998 ◽  
Vol 4 (S2) ◽  
pp. 716-717
Author(s):  
S.A. Harfenist ◽  
Z.L. Wang ◽  
T.G. Schaaff ◽  
R.L. Whettent
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Nanometer Scale ◽  
Core Diameter ◽  
Ordered Structures ◽  
Gold Nanocrystals ◽  
Transmission Electron ◽  
Assembled Monolayers

A recent development in the study of nanocrystalline materials has been the self-assembly of passivated nanometer scale building blocks into larger, well ordered structures reaching the micron scale. Nanocrystal supercrystals (NCS) have been observed in metallic, semiconductor, and magnetic materials. In most cases the nanocrystals (NXs) are encapsulated in some inert medium that effectively protects the nanocrystal core and its unique electronic and optical properties. Here we describe the self-assembly of gold nanocrystals (∼4.5 nm core diameter), passivated with hexanethiol self-assembled-monolayers into ordered regions exhibiting a body-centered-cubic (bcc) superstructure. Transmission Electron Microscopy (TEM) imaging and Electron Diffraction (ED) experiments were used to characterize the NCSs and their resulting superstructures.A large agglomeration of NCSs can be seen in figure 1. One can clearly see regions of periodicity within the nanocrystal aggregation.

Stochastic Computing via In Operando Modulation of Rectification in Molecular Tunneling Junctions

2020 ◽  
Author(s):  
Xinkai Qiu ◽  
Sylvia Rousseva ◽  
Gang Ye ◽  
Jan C. Hummelen ◽  
Ryan Chiechi
Keyword(s):  
Self Assembly ◽  
Variable Temperature ◽  
Self Assembled Monolayers ◽  
Microfluidic Channels ◽  
Proof Of Concept ◽  
Glycol Ethers ◽  
Stochastic Computing ◽  
Assembled Monolayers ◽  
In Operando ◽  
Tunneling Junctions

This paper describes the reconfiguration of molecular tunneling junctions during operation via the self-assembly of bilayers of glycol ethers. We use well-established functional groups to modulate the magnitude and direction of rectification in assembled tunneling junctions by exposing them to solutions containing different glycol ethers. Variable-temperature measurements establish that rectification occurs by a bias-dependent tunneling-hopping mechanism and that glycol ethers, beside being an unusually efficient tunneling medium, behave identically to alkanes. We fabricated memory bits from crossbar junctions prepared by injecting eutectic Ga-In into microfluidic channels. Two 8-bit registers were able to perform logical AND operations on bit strings encoded into chemical packets as microfluidic droplets that alter the composition of the crossbar junctions through self-assembly to effect memristor-like properties. This proof of concept work demonstrates the potential for fieldable molecular-electronic devices based on tunneling junctions of self-assembled monolayers and bilayers.

Synthesis of Dehydrobenzo[18]annulene Derivatives and Formation of Self-Assembled Monolayers:  Implications of Core Size on Alkyl Chain Interdigitation

Langmuir ◽  
2007 ◽  
Vol 23 (20) ◽  
pp. 10190-10197 ◽  
Author(s):  
Kazukuni Tahara ◽  
Charles A. Johnson ◽  
Takumi Fujita ◽  
Motohiro Sonoda ◽  
Frans C. De Schryver ◽  
...  
Keyword(s):  
Alkyl Chain ◽  
Self Assembled Monolayers ◽  
Core Size ◽  
Assembled Monolayers ◽  
Self Assembled

Self-assembly of biomolecules at surfaces characterized by NEXAFS

2007 ◽  
Vol 85 (10) ◽  
pp. 793-800 ◽  
Author(s):  
Xiaosong Liu ◽  
Fan Zheng ◽  
A Jürgensen ◽  
V Perez-Dieste ◽  
D Y Petrovykh ◽  
...  
Keyword(s):  
Surface Science ◽  
Self Assembly ◽  
Ribonuclease A ◽  
Polarization Dependence ◽  
Biological Molecules ◽  
Self Assembled Monolayers ◽  
Peptide Bonds ◽  
Molecular Adsorbates ◽  
Dna Oligonucleotides ◽  
Assembled Monolayers

Surface science has made great strides towards tailoring surface properties via self-assembly of nanoscale molecular adsorbates. It is now possible to functionalize surfaces with complex biomolecules such as DNA and proteins. This brief overview shows how NEXAFS (near edge X-ray absorption fine structure spectroscopy) can be used to characterize the assembly of biological molecules at surfaces in atom- and orbital-specific fashion. To illustrate the range of applications, we begin with simple self-assembled monolayers (SAMs), proceed to SAMs with customized terminal groups, and finish with DNA oligonucleotides and Ribonuclease A, a small protein containing 124 amino acids. The N 1s absorption edge is particularly useful for characterizing DNA and proteins because it selectively interrogates the π* orbitals in nucleobases and the peptide bonds in proteins. Information about the orientation of molecular orbitals is obtained from the polarization dependence. Quantitative NEXAFS models explain the polarization dependence in terms of molecular orientation and structure.Key words: NEXAFS, bio-interfaces, ribonuclease A, immobilization, orientation.

Assesment of Vibrational Coupling at Solid-SAM Junctions

2011 ◽  
Author(s):  
Christopher B. Saltonstall ◽  
John C. Duda ◽  
Patrick E. Hopkins ◽  
Pamela M. Norris
Keyword(s):  
Thermal Conductance ◽  
Chemical Properties ◽  
Self Assembled Monolayers ◽  
Vibrational Coupling ◽  
Thermal Boundary Conductance ◽  
Hartree Fock ◽  
Assembled Monolayers ◽  
Methylene Groups ◽  
Methylene Group ◽  
And Chemical Properties

Self-assembled monolayers (SAMs) have recently garnered much interest due to their unique electrical and chemical properties. The limited literature detailing SAM thermal properties has suggested that thermal boundary conductance (TBC) at solid-SAM junctions is not only low, but also insensitive to changes in SAM length as the number of methylene groups (-CH2-) along alkanedithiol chains is varied from 8 to 10. The present study investigates the vibrational spectra of alkanedithiol SAMs as a function of the number of methylene groups forming the molecule backbone via Hartree-Fock methods and the subsequent effects on TBC calculated using a diffuse scattering model. In particular, the vibrational overlap between the alkanedithiol and Au is studied. It is found that despite the addition of 9 new vibrational modes per added methylene group, only one of those modes is elastically accessible to Au. It is believed that this “vibrational inaccessibility” is the cause of the insensitivity of thermal conductance to molecule length.

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