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 Thiocyanate Anchors for Salt-like Iron(II) Complexes on Au(111): Promises and Caveats

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1164-1180 ◽  
Author(s):  
Philipp Stock ◽  
Andreas Erbe ◽  
Manfred Buck ◽  
Dennis Wiedemann ◽  
Hervé Ménard ◽  
...  
Keyword(s):  
Gold Surface ◽  
Self Assembled Monolayers ◽  
Sulphur Atom ◽  
X Ray ◽  
New Class ◽  
Scanning Tunnelling ◽  
Assembled Monolayers ◽  
Tunnelling Microscopy ◽  
Self Assembled ◽  
Ionic Iron

Abstract The formation of self-assembled monolayers (SAMs) on Au(111) from solution has been investigated for two ionic iron(II) complexes of the type [Fe(L)](BF4)2, where L is tripodal hexadentate and contains three thiocyanate anchor groups. The ligands (L1, L2; donor set: N6) are obtained by Schiff base condensation of a tripodal triamine (L1: tris-(2-aminoethyl)amine, ‘tren’; L2: 1,1′,1″- trimethyl(thiophosphoryl)trihydrazide) with 5-(4-thiocyanatobutoxy) pyridine-2-carbaldehyde. Layers of the complexes adsorbed on Au(111) from methanol solution have been characterised using scanning tunnelling microscopy (STM), infrared reflectance absorbance (IRRAS), X-ray photoelectron (XPS) and UV=Vis reflectance spectroscopies, as well as ellipsometry. Complex [Fe(L1)](BF4)2 deposits intact on a gold surface and retains its optical addressability. Elaboration of this result may provide access to a new class of self-assembled layers, employing salt-like tripodal coordination compounds with thiocyanate anchors. The second complex, [Fe(L2)](BF4)2, which contains a sulphur atom in the ligand backbone, is not sufficiently stable under the same conditions.

Scanning tunnelling microscopy investigations of self-assembled monolayers of poly(3-decyl-thiophene) on graphite

1993 ◽  
Vol 2 (6) ◽  
pp. 295-299 ◽  
Author(s):  
Annalisa Bonfiglio ◽  
Rita Paradiso ◽  
Ermanno Di Zitti ◽  
Davide Ricci ◽  
Alberto Bolognesi ◽  
...  
Keyword(s):  
Scanning Tunnelling Microscopy ◽  
Self Assembled Monolayers ◽  
Scanning Tunnelling ◽  
Assembled Monolayers ◽  
Tunnelling Microscopy ◽  
Self Assembled

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.

Comparative Molecular Dynamics Study of Aβ Adsorption on the Self-Assembled Monolayers

Langmuir ◽  
2010 ◽  
Vol 26 (5) ◽  
pp. 3308-3316 ◽  
Author(s):  
Qiuming Wang ◽  
Chao Zhao ◽  
Jun Zhao ◽  
Jingdai Wang ◽  
Jui-Chen Yang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
The Self ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

scholarly journals Corrosion Protection of AA7075 Aluminium Alloy by Trimethoxy-Silanes Self-Assembled Monolayers

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Rodrigo S. Neves ◽  
Daiane P. B. Silva ◽  
Artur J. Motheo
Keyword(s):  
Aluminium Alloy ◽  
Electrochemical Impedance ◽  
Protective Coatings ◽  
Reduction Reaction ◽  
Self Assembled Monolayers ◽  
Organic Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Surface Modified ◽  
Trimethoxy Silane

This study presents electrochemical data concerning the aluminium alloy AA7075 surface modified by self-assembled monolayers (SAMs) of octadecyl-trimethoxy-silane and propyl-trimethoxy-silane. Polarisation curves have shown SAMs blocking effect, as they partially block the oxygen reduction reaction and displace the corrosion potential to positive values. Electrochemical impedance spectroscopy experiments have suggested that the protective effect comes from the oxide layer stabilization by the organic monolayers, which block the corroding species diffusion to the surface. These results show the potential of using methoxy-silanes SAMs as corrosion protective coatings; however, they are also indicative of the superior octadecyl-trimethoxy-silane protective characteristics.

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