We report a scanning tunneling microscopy (STM) study of the molecular self-assembly of biphenyl-3,3',5,5'-tetracarboxylic acid (BPTC) at the octanoic acid/graphite interface. STM revealed that the BPTC molecules generated stable bilayers and monolayers under high and low sample concentrations, respectively. Besides hydrogen bonds, the bilayers were stabilized by molecular π-stacking, whereas the monolayers were maintained by solvent co-adsorption. A thermodynamically stable Kagomé structure was obtained upon mixing BPTC with coronene (COR), while kinetic trapping of COR in the co-crystal structure was found by the subsequent deposition of COR onto a preformed BPTC bilayer on the surface. Force field calculation was conducted to compare the binding energies of different phases, which helped to provide plausible explanations for the structural stability formed via kinetic and thermodynamic pathways.
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http://dx.doi.org/10.1021/acs.langmuir.2c03199 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
University of Kiel, Physics, Olshausenstr. 40, 24098, Kiel, GERMANY.
The influence of coadsorbed ions on adsorbate diffusion, an inherent effect at solid-liquid interfaces, was studied for adsorbed sulfur on Ag(100) electrodes in the presence of bromide or iodide. Quantitative in situ high-speed scanning tunnelling microscopy (video-STM) measurements were performed both in the potential regime of the c(2×2) halide adlayer at its saturation coverage and in the regime of a disordered adlayer where the halide coverage increases with potential. These studies reveal a surprising non-monotonic potential dependence of Sad diffusion with an initial increase with halide coverage, followed by a decrease upon halide adlayer ordering into the c(2×2) structure.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Max Planck-EPFL Laboratory for Molecular Nanoscience, Institut de Physique de la Matière Condensée, École Polytechnique Fédérale de Lausanne, CH 1015 Lausanne, Switzerland, 1005, Lausanne, SWITZERLAND.
Efficient catalytic water splitting demands advanced catalysts to improve the slow kinetics of the oxygen evolution reaction (OER). Earth-abundant transition metal oxides show promising OER activity in alkaline media. However, most experimental information available is either from post-mortem studies or in-situ space-averaged X-ray techniques in the micrometer range.
View Article and Find Full Text PDFSci Transl Med
January 2025
Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, 81377 Munich, Germany.
In Alzheimer's disease (AD), amyloid-β (Aβ) triggers the aggregation and spreading of tau pathology, which drives neurodegeneration and cognitive decline. However, the pathophysiological link between Aβ and tau remains unclear, which hinders therapeutic efforts to attenuate Aβ-related tau accumulation. Aβ has been found to trigger neuronal hyperactivity and hyperconnectivity, and preclinical research has shown that tau spreads across connected neurons in an activity-dependent manner.
View Article and Find Full Text PDFAvian Pathol
January 2025
São Paulo State University (UNESP), School of Agricultural and Veterinary Sciences, Jaboticabal, SP, 14884-900, Brazil.
It was previously reported that utilization of tetrathionate and 1,2-propanediol by spp. through the metabolic pathways encoded by and operons are related to overgrowth and out-competing microbiota in an anaerobic environment. However, recent knowledge demonstrated which strains in the absence of and genes provoke both higher intestinal colonization and spreading bacteria on faeces in relation to their respective wild-type strain, and generate more prominent inflammation as well.
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