Single layers of covalently linked organic materials in the form of two-dimensional (2D) polymers constitute structures complementary to inorganic 2D materials. The electronic properties of 2D polymers may be manipulated through a deliberate choice of the organic precursors. Here we address the changes in electronic structure-from precursor molecule to oligomer-by scanning tunneling spectroscopy and ultraviolet photoelectron spectroscopy. For this purpose, we introduce the polymerization reaction of 1,3,5-tris(4-carboxyphenyl)benzene via decarboxylation on Cu(111), which is thoroughly characterized by scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory calculations. We present a comprehensive study of a contamination-free on-surface coupling scheme and study how dehydrogenation, decarboxylation, and polymerization affect the electronic structure on the molecular level.
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http://dx.doi.org/10.1021/acsnano.6b07314 | DOI Listing |
Anal Chem
January 2025
Institute for Advanced Optics, Hunan Institute of Science and Technology, Yueyang, Hunan 414006, China.
Diffraction imaging of cells allows rapid phenotyping by the response of intracellular molecules to coherent illumination. However, its ability to distinguish numerous types of human leukocytes remains to be investigated. Here, we show that accurate classification of three lymphocyte subtypes can be achieved with features extracted from cross-polarized diffraction image (p-DI) pairs.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Medak 502 284, Telangana, India.
The topological properties of the A15-type compound TiPd reveal a complex landscape of multi-fold fermionic and bosonic states, as uncovered through calculations within the framework of density functional theory (DFT). The electronic band structure shows multi-fold degenerate crossings at the high-symmetry point R near the Fermi level, which evolves into 4-fold and 8-fold degenerate fermionic states upon the introduction of spin-orbit coupling (SOC). Likewise, the phononic band structure features multi-fold degenerate bosonic crossings at the same R point.
View Article and Find Full Text PDFJ Acoust Soc Am
January 2025
School of Integrated Circuits, Tsinghua University, Beijing 100084, China.
In shallow water, reverberation complicates the detection of low-intensity, variable-echo moving targets, such as divers. Traditional methods often fail to distinguish these targets from reverberation, and data-driven methods are constrained by the limited data on intruding targets. This paper introduces the online robust principal component analysis and multimodal anomaly detection (ORMAD) method to address these challenges.
View Article and Find Full Text PDFChemphyschem
January 2025
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, PS-ISRR, GERMANY.
Two-dimensional layered double hydroxides (LDHs) are ideal candidates for a large number of (bio)catalytic applications due to their flexible composition and easy to tailor properties. Functionality can be achieved by intercalation of amino acids (as the basic units of peptides and proteins). To gain insight on the functionality, we apply resonant inelastic soft x-ray scattering and near edge x-ray absorption fine structure spectroscopy to CaFe LDH in its pristine form as well as intercalated with the amino acids proline and cysteine to probe the electronic structure and its changes upon intercalation.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany.
X-ray spectroscopies are uniquely poised to describe the geometric and electronic structure of metalloenzyme active sites under a wide variety of sample conditions. UV/Vis (ultraviolet/visible) spectroscopy is a similarly well-established technique that can identify and quantify catalytic intermediates. The work described here reports the first simultaneous collection of full in situ UV/Vis and high-energy resolution fluorescence detected x-ray absorption spectra.
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