A study of the deposition of heterometallic antiferromagnetically coupled rings onto gold surfaces is reported. Two new {Cr7Ni} rings, [NH2nPr2][Cr7NiF8(3-tpc)16] (1) (where 3-tpc=3-thiophenecarboxylate) and [nBuNH2CH2CH2SH] [Cr7NiF8(O2CtBu)16] (2) have been made and structurally characterized. They have been deposited from the liquid phase on Au(111) and the adsorbed molecules compared by means of scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS). In both cases a two-dimensional distribution of individually accessible {Cr7Ni} heterometallic rings on the gold surface has been obtained, exploiting the direct grafting of sulfur-functionalized clusters. There is a competition between the chemisorption of the {Cr7Ni} clusters and a thiolic self-assembled monolayer (SAM) formed by free ligands. In 2, the presence of a single sulfur ligand should force the molecule to graft with the ring axis normal to the surface. The cluster stability in the STM images and the S-2p energy positions demonstrate, for both functionalizations, the strength of the grafting with the gold surface.
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http://dx.doi.org/10.1021/ic0624266 | DOI Listing |
Phys Chem Chem Phys
December 2024
Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
Understanding electron transport in self-assembled monolayers on metal nanoparticles (NPs) is crucial for developing NP-based nanodevices. This study investigates ultrafast electron transport through aromatic molecules on NP surfaces resonant Auger electron spectroscopy (RAES) with a core-hole-clock (CHC) approach. Aromatic molecule-coated Au NPs are deposited to form condensed NP films, and flat monolayers are prepared for comparison.
View Article and Find Full Text PDFJ Org Chem
December 2024
College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, P. R. China.
Nanophotonics
December 2023
State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China.
Optical vortices (OVs), as eigenmodes of optical orbital angular momentum, have been widely used in particle micro-manipulation. Recently, perfect optical vortices (POVs), a subclass of OVs, are gaining increasing interest and becoming an indispensable tool in optical trapping due to their unique property of topological charge-independent vortex radius. Here, we expand the concept of POVs by proposing concentric ring optical traps (CROTs) and apply them to trapping and rotating particles.
View Article and Find Full Text PDFJ Mol Model
November 2024
Department of Chemistry, Can Tho University, Can Tho, 90000, Vietnam.
Context: While the pure Au cluster tends to exist in a 3D cage shape, the doubly doped W@Au is found to prefer a tubular form containing three five-membered Au rings stabilized by the W dimer vertically placed inside a tube-like Au framework. Formation of self-assembled nanotubes containing five-membered Au rings from the tube-like W@Au cluster is also feasible, and such a tubular structure constitutes an ideal building block for generating gold-assembled nanotubes, providing us with a useful approach for designing some novel tailor-made materials with interesting optoelectronic properties.
Methods: Density functional theory (DFT) calculations using the TPSS functional and the cc-pVDZ-PP basis set are employed to determine some noticeable effects of the doping of the W dimer on the structure, stability, and optical properties of pure Au16 gold clusters.
Terahertz (THz) metasurfaces provide unprecedented abilities to realize versatile THz wavefronts manipulations. Nevertheless, these high degree of freedom, non-periodic, densely arranged subwavelength unit cells pose numerous extreme parameter requirements for the fabrication of metasurfaces, presenting significant challenges to their practical application. Herein, a spatial shaping femtosecond laser printing system, based on spatial light modulation (SLM), is proposed for the creation of THz metasurfaces.
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