The role of the inorganic substrate termination, within the organic-inorganic interface, has been well studied for systems that contain strong localised bonding. However, how varying the substrate termination affects coordination to delocalised electronic states, like that found in aromatic molecules, is an open question. Azupyrene, a non-alternant polycyclic aromatic hydrocarbon, is known to bind strongly to metal surfaces through its delocalised π orbitals, thus yielding an ideal probe into delocalised surface-adsorbate interactions.
View Article and Find Full Text PDFDefects play a critical role for the functionality and performance of materials, but the understanding of the related effects is often lacking, because the typically low concentrations of defects make them difficult to study. A prominent case is the topological defects in two-dimensional materials such as graphene. The performance of graphene-based (opto-)electronic devices depends critically on the properties of the graphene/metal interfaces at the contacting electrodes.
View Article and Find Full Text PDFPyrene derivatives play a prominent role in organic electronic devices, including field effect transistors, light emitting diodes, and solar cells. The flexibility in the desired properties has previously been achieved by variation of substituents at the periphery of the pyrene backbone. In contrast, the influence of the topology of the central π-electron system on the relevant properties such as the band gap or the fluorescence behavior has not yet been addressed.
View Article and Find Full Text PDFThe synthesis of 1,3-oxazoles from symmetrical and unsymmetrical alkynes was realized by an iodonium cation-pool electrolysis of I in acetonitrile with a well-defined water content. Mechanistic investigations suggest that the alkyne reacts with the acetonitrile-stabilized I ions, followed by a Ritter-type reaction of the solvent to a nitrilium ion, which is then attacked by water. The ring closure to the 1,3-oxazoles released molecular iodine, which was visible by the naked eye.
View Article and Find Full Text PDFThe cobalt-catalyzed hydrovinylation reaction and the Alder-ene reaction generate acyclic 1,4-dienes, which were investigated in the selenium dioxide oxidation to afford further functionalized dienes prone for follow-up reactions. The chemoselective allylic oxidation of ester-functionalized 1,4-dienes occurs at the most electron-rich double bond. The steric demand of the electron-rich, alkyl-substituted double bond determines the reaction pathway, whether the double bond transposition toward the conjugated 1,3-diene or the allylic oxidation is faster.
View Article and Find Full Text PDFA novel approach of electrolysis using alternating current was applied in the sulfur-sulfur bond metathesis of symmetrical disulfides towards unsymmetrical disulfides. As initially expected, a statistical distribution in disulfides was obtained. Furthermore, the influence of electrode polarisation by alternating current was investigated on a two-disulfide matrix.
View Article and Find Full Text PDFPurpose: Since the introduction of Ga-PSMA-11 PET/CT for imaging prostate cancer (PC) we have frequently observed mediastinal lymph nodes (LN) showing tracer uptake despite being classified as benign. The aim of this evaluation was to further analyze such LN.
Methods: Two patient groups with biphasic Ga-PSMA-11 PET/CT at 1 h and 3 h p.
An iron pincer complex containing a hemi-labile (R P) BH group exhibits temperature-switchable reactivity patterns: a reversible B-H activation concomitant with a P-B bond cleavage is observed at room temperature. Below 4 °C, intra- and intermolecular C-H activation pathways are becoming faster and more dominant. Mechanistic investigations reveal that the lability of the (R P) BH group in combination with the exothermic formation of σ-bonded complexes are responsible for the switchable bond activation.
View Article and Find Full Text PDFAlthough PET/CT with Ga-PSMA-11 in the diagnosis of prostate cancer (PCa) is routinely performed at 1 h after injection, later scans may be beneficial because most lesions present with higher uptake and contrast. This evaluation aimed to investigate the clinical impact of additional late Ga-PSMA-11 PET/CT. Between 2011 and 2016, 112 patients with PCa who underwent early (at 1 h after injection) and late (at 3 h after injection) Ga-PSMA-11 PET/CT scans were retrospectively evaluated.
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