scholarly journals Fabrication of Photomagnetic Carbon Surfaces via Redox Assembly

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Y.-L. Song ◽  
C. M. Wang
Keyword(s):  
Ruthenium Complex ◽  
Pyrolytic Graphite ◽  
Building Blocks ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Highly Ordered Pyrolytic Graphite ◽  
Ester Formation ◽  
Aminophenylboronic Acid ◽  
Carbon Surfaces ◽  
Reaction Stoichiometry

3-Aminophenylboronic acid (APBA) and the complex Ru(bpy)2(phendione)2+ (bpy = 2,2′-bipyridine, phendione = 1,10-phenanthroline-5,6-dione) were found to be useful building blocks for preparing photomagnetic carbon surfaces. Scanning tunneling microscopy (STM) showed that when APBA was diazotized in acidic sodium nitrite solutions and cathodically reduced with highly ordered pyrolytic graphite (HOPG) electrodes, nanoscale films formed on the electrodes. The resulting HOPG had strong affinities for phendione and Ru(bpy)2(phendione)2+ as the electrodes were biased in the presence of them, respectively, with voltages more negative than the cathodic peak potentials for phendione/phendiol and Ru(bpy)2(phendione)2+/Ru(bpy)2(phendiol)2+ (phendiol = 1,10-phenanthroline-5,6-diol). However, if APBA was excluded, the affinities did not exist. Boronate ester formation featured prominently in these intermolecular interactions. The average increments in the HOPG surface roughness contributed by APBA and Ru(bpy)2(phendione)2+ were roughly 1 : 2, suggesting that the reaction stoichiometry between APBA and Ru(bpy)2(phendione)2+ be 1 : 1. Ru(bpy)2(phendione)2+ could also be grafted to carbon nanotubes (CNTs) under conditions similar to those for the HOPG using ascorbate as sacrificial donor. The resulting CNTs and HOPG exhibited photomagnetism when exposed to the 473 nm light. The ruthenium complex was shown to be a room-temperature photomagnetism precursor, and APBA was shown to be an effective molecular bridge for the complex and carbon substrates.

HYDROGEN-BONDED STRUCTURES OF TRIMESIC AND MELAMINE ON HIGHLY ORIENTED PYROLYTIC GRAPHITE

2014 ◽  
Vol 21 (03) ◽  
pp. 1450035 ◽  
Author(s):  
LING ZHU ◽  
XUMING XU ◽  
YAN WANG ◽  
SHUYI LIU ◽  
JIE LING ◽  
...  
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Functional Groups ◽  
Guest Molecule ◽  
Pyrolytic Graphite ◽  
Building Blocks ◽  
Scanning Tunneling ◽  
Porous Structures ◽  
Highly Oriented Pyrolytic Graphite ◽  
Tunneling Microscopy ◽  
Trimesic Acid

The assembled structures of triangular symmetrically shape molecules with three functional groups, trimesic acid (TMA) and melamine, have been investigated by scanning tunneling microscopy on Highly Oriented Pyrolytic Graphite (HOPG) in ambient. Hexagonal porous structures are formed by these molecules and the cavity of the assembled structure becomes bigger when larger molecules are used as building blocks. The cavity within the assembled structure formed by TMA is bigger enough to host guest molecule.

Ordering of a Functional Molecules on a Flat Surface as Evidenced by Scanning Probe Microscopies: The Case of a Di-Alkyl Amino Group

1998 ◽  
Vol 4 (S2) ◽  
pp. 304-305
Author(s):  
Christopher Gorman ◽  
Igor Touzov ◽  
Russell Miller
Keyword(s):  
Flat Surface ◽  
Pyrolytic Graphite ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Distinctive Features ◽  
Atomic Force ◽  
Highly Ordered Pyrolytic Graphite ◽  
Organic Functional Groups ◽  
Packing Arrangement

Our group is interested in exploring how functional molecules (e.g. those composed of organic functional groups that do not necessarily lend themselves to an ordered 2D packing arrangement) can form well-ordered adlayers with functional properties. To this end. we have studied the formation of self assembled structures of 5-(N,N-didecyl-amino)-2.4- pentadienal (DAPDA, Figure 1) deposited on a highly ordered pyrolytic graphite (HOPG) surface. This molecule has two distinctive features that should dramatically affect its ordering on a surface. Neither of these have been systematically explored in ordered adlayers. First, the extended conjugation of the molecule gives it a large in-plane dipole moment as well as a high polarizability. Second, it contains two hydrocarbon tails, only one of which can lie coplanar with the conjugated moiety. Both molecularly resolved monolayer and bilayer structures were found using a combination of scanning tunneling microscopy and tapping mode atomic force microscopies.

scholarly journals Ester formation at the liquid–solid interface

2017 ◽  
Vol 8 ◽  
pp. 2139-2150 ◽  
Author(s):  
Nguyen T. N. Ha ◽  
Thiruvancheril G Gopakumar ◽  
Nguyen D. C. Yen ◽  
Carola Mende ◽  
Lars Smykalla ◽  
...  
Keyword(s):  
Deposition Temperature ◽  
Pyrolytic Graphite ◽  
Alcoholic Solution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Regular Array ◽  
Trimesic Acid ◽  
Solid Interface ◽  
Ester Formation ◽  
Adsorbate Layer

A chemical reaction (esterification) within a molecular monolayer at the liquid–solid interface without any catalyst was studied using ambient scanning tunneling microscopy. The monolayer consisted of a regular array of two species, an organic acid (trimesic acid) and an alcohol (undecan-1-ol or decan-1-ol), coadsorbed out of a solution of the acid within the alcohol at the interface of highly oriented pyrolytic graphite (HOPG) (0001) substrate. The monoester was observed promptly after reaching a threshold either related to the increased packing density of the adsorbate layer (which can be controlled by the concentration of the trimesic acid within the alcoholic solution via sonication or extended stirring) or by reaching a threshold with regards to the deposition temperature. Evidence that esterification takes place directly at the liquid–solid interface was strongly supported.

scholarly journals Syntheses and properties of thienyl-substituted dithienophenazines

2010 ◽  
Vol 6 ◽  
pp. 1180-1187 ◽  
Author(s):  
Annemarie Meyer ◽  
Eva Sigmund ◽  
Friedhelm Luppertz ◽  
Gregor Schnakenburg ◽  
Immanuel Gadaczek ◽  
...  
Keyword(s):  
Density Functional ◽  
Pyrolytic Graphite ◽  
Electron Donors ◽  
Time Dependent ◽  
Self Assembled Monolayers ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Functional Theory ◽  
Highly Ordered Pyrolytic Graphite ◽  
Assembled Monolayers

A series of dithienophenazines with different lengths of the oligomeric thiophene units (quaterthiophenes and sexithiophenes) was synthesized. The thiophene and phenazine units act as electron donors and acceptors, respectively, resulting in characteristic absorption spectra. The optical spectra were calculated using time-dependent density functional theory at the B3LYP/TZVP level and verify the experimental data. Adsorption of the dithienophenazines on highly ordered pyrolytic graphite (HOPG) was investigated by scanning tunneling microscopy, showing that one of the compounds forms highly organized self-assembled monolayers.

scholarly journals Scanning Tunneling Microscope Investigation of Self-Assembled Rosette Nanotubes on Highly Ordered Pyrolytic Graphite

2010 ◽  
Vol 16 (S2) ◽  
pp. 470-471 ◽  
Author(s):  
J-Y Cho ◽  
G Borzsonyi ◽  
H Fenniri
Keyword(s):  
Scanning Tunneling Microscope ◽  
Pyrolytic Graphite ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Microscope Investigation ◽  
Rosette Nanotubes ◽  
Highly Ordered Pyrolytic Graphite ◽  
Self Assembled

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

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