Deliang Bao | Vanderbilt University (original) (raw)
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Papers by Deliang Bao
Nature communications, Aug 16, 2018
Site-selective functionalization of only one of two identical chemical groups within one molecule... more Site-selective functionalization of only one of two identical chemical groups within one molecule is highly challenging, which hinders the production of complex organic macromolecules. Here we demonstrate that adsorption of 4,4″-diamino-p-terphenyl on a metal surface leads to a dissymmetric binding affinity. With low temperature atomic force microscopy, using CO-tip functionalization, we reveal the asymmetric adsorption geometries of 4,4″-diamino-p-terphenyl on Cu(111), while on Au(111) the symmetry is retained. This symmetry breaking on Cu(111) is caused by a lattice mismatch and interactions with the subsurface atomic layer. The dissymmetry results in a change of the binding affinity of one of the amine groups, leading to a non-stationary behavior under the influence of the scanning tip. Finally, we exploit this dissymmetric binding affinity for on-surface self-assembly with 4,4″-diamino-p-terphenyl for side-preferential attachment of 2-triphenylenecarbaldehyde. Our findings provi...
The Journal of Physical Chemistry C
Applied Physics Letters, 2016
Chinese Physics B, 2015
Adsorption behavior of Fe atoms on a metal-free naphthalocyanine (H 2 Nc) monolayer on Ag(111) su... more Adsorption behavior of Fe atoms on a metal-free naphthalocyanine (H 2 Nc) monolayer on Ag(111) surface at room temperature has been investigated using scanning tunneling microscopy combined with density functional theory (DFT) based calculations. We found that the Fe atoms were adsorbed on the centers of H 2 Nc molecules and formed Fe-H 2 Nc complexes at low coverage. DFT calculations show that Fe sited in the center of the molecule is the most stable configuration, in good agreement with the experimental observations. After an Fe-H 2 Nc complex monolayer was formed, the extra Fe atoms self-assembled to Fe clusters of uniform size and adsorbed dispersively at the interstitial positions of Fe-H 2 Nc complex monolayer. Therefore, the H 2 Nc monolayer grown on Ag(111) could be a good template to grow dispersed magnetic metal atoms and clusters at room temperature for further investigation of their magnetism-related properties.
The Journal of Physical Chemistry C, 2015
ABSTRACT Structural and mechanical properties of self-assembled metal-free naphthalocyanine (H2Nc... more ABSTRACT Structural and mechanical properties of self-assembled metal-free naphthalocyanine (H2Nc) films on a Ag(111) surface are studied. Six self-assembled domains are observed by scanning tunneling microscopy (STM). Combining the high-resolution STM images and density functional theory (DFT) based calculations, we found that molecules adsorbed flatly on the substrate by forming six different interlocked square-like unit cells with different lattice parameters. DFT calculations indicated comparable adsorption energies for all the configurations. Six domains with different lattice parameters present different strain states, giving us a possibility to evaluate the Young’s modulus of the metal-free naphthalocyanine films on Ag(111) surface. We found that the Young’s modulus of H2Nc is comparable to those of typical conjugated organic-molecule based crystals (e.g., naphthalene), providing useful information for future applications when the elastic properties should be concerned.
Nature communications, Aug 16, 2018
Site-selective functionalization of only one of two identical chemical groups within one molecule... more Site-selective functionalization of only one of two identical chemical groups within one molecule is highly challenging, which hinders the production of complex organic macromolecules. Here we demonstrate that adsorption of 4,4″-diamino-p-terphenyl on a metal surface leads to a dissymmetric binding affinity. With low temperature atomic force microscopy, using CO-tip functionalization, we reveal the asymmetric adsorption geometries of 4,4″-diamino-p-terphenyl on Cu(111), while on Au(111) the symmetry is retained. This symmetry breaking on Cu(111) is caused by a lattice mismatch and interactions with the subsurface atomic layer. The dissymmetry results in a change of the binding affinity of one of the amine groups, leading to a non-stationary behavior under the influence of the scanning tip. Finally, we exploit this dissymmetric binding affinity for on-surface self-assembly with 4,4″-diamino-p-terphenyl for side-preferential attachment of 2-triphenylenecarbaldehyde. Our findings provi...
The Journal of Physical Chemistry C
Applied Physics Letters, 2016
Chinese Physics B, 2015
Adsorption behavior of Fe atoms on a metal-free naphthalocyanine (H 2 Nc) monolayer on Ag(111) su... more Adsorption behavior of Fe atoms on a metal-free naphthalocyanine (H 2 Nc) monolayer on Ag(111) surface at room temperature has been investigated using scanning tunneling microscopy combined with density functional theory (DFT) based calculations. We found that the Fe atoms were adsorbed on the centers of H 2 Nc molecules and formed Fe-H 2 Nc complexes at low coverage. DFT calculations show that Fe sited in the center of the molecule is the most stable configuration, in good agreement with the experimental observations. After an Fe-H 2 Nc complex monolayer was formed, the extra Fe atoms self-assembled to Fe clusters of uniform size and adsorbed dispersively at the interstitial positions of Fe-H 2 Nc complex monolayer. Therefore, the H 2 Nc monolayer grown on Ag(111) could be a good template to grow dispersed magnetic metal atoms and clusters at room temperature for further investigation of their magnetism-related properties.
The Journal of Physical Chemistry C, 2015
ABSTRACT Structural and mechanical properties of self-assembled metal-free naphthalocyanine (H2Nc... more ABSTRACT Structural and mechanical properties of self-assembled metal-free naphthalocyanine (H2Nc) films on a Ag(111) surface are studied. Six self-assembled domains are observed by scanning tunneling microscopy (STM). Combining the high-resolution STM images and density functional theory (DFT) based calculations, we found that molecules adsorbed flatly on the substrate by forming six different interlocked square-like unit cells with different lattice parameters. DFT calculations indicated comparable adsorption energies for all the configurations. Six domains with different lattice parameters present different strain states, giving us a possibility to evaluate the Young’s modulus of the metal-free naphthalocyanine films on Ag(111) surface. We found that the Young’s modulus of H2Nc is comparable to those of typical conjugated organic-molecule based crystals (e.g., naphthalene), providing useful information for future applications when the elastic properties should be concerned.