Pyrimidoquinazolinophenanthroline Opens Next Chapter in Design of Bridging Ligands for Artificial Photosynthesis**

The synthesis and detailed characterization of a new Ru polypyridine complex containing a heteroditopic bridging ligand with previously unexplored metal-metal distances is presented. Due to the twisted geometry of the novel ligand, the resultant division of the ligand in two distinct subunits leads to steady state as well as excited state properties of the corresponding mononuclear Ru(II) polypyridine complex resembling those of prototype [Ru(bpy)₃]²⁺ (bpy=2,2'-bipyridine). The localization of the initially optically excited and the nature of the long-lived excited states on the Ru-facing ligand spheres is evaluated by resonance Raman and fs-TA spectroscopy, respectively, and supported by DFT and TDDFT calculations. Coordination of a second metal (Zn or Rh) to the available bis-pyrimidyl-like coordination sphere strongly influences the frontier orbitals, apparent by, for example, luminescence quenching. Thus, the new bridging ligand motif offers electronic properties, which can be adjusted by the nature of the second metal center. Using the heterodinuclear Ru−Rh complex, visible light-driven reduction of NAD⁺ to NADH was achieved, highlighting the potential of this system for photocatalytic applications.     

Geometric scaling in inclusive eA reactions and nonlinear perturbative QCD

We report on geometric scaling in inclusive eA scattering data from the NMC and E665 experiments. This scaling and nuclear shadowing follows the pattern expected from nonlinear perturbative QCD for zero impact parameter at sufficiently small x(bj) and is compatible with geometric scaling in ep.     

Simultaneous, quantitative analysis of UDP-N-acetylglucosamine, UDP-N-acetylgalactosamine, UDP-glucose and UDP-galactose in human peripheral blood cells, muscle biopsies and cultured mesangial cells by capillary zone electrophoresis

The aim of this study was to develop and evaluate a capillary zone electrophoretic (CE) procedure for the accurate quantification of the UDP-hexosamines as well as for the corresponding UDP-hexoses in samples from various biological origins. Testing different buffer conditions, voltages, capillary dimensions and temperatures, optimal results were achieved with a 90 mM borate buffer, pH 9.0, at 18 degrees C and 15.5 kV in an uncoated fused-silica capillary of 50 cm x 50 microm and a detection wavelength of lambda = 262 nm. The total procedure, i.e., including variations of the sample preparation, showed coefficients of variation for the peak areas between 4. 1% and 10.4% in mesangial cells (n = 7) and between 7.8 and 10.3% (n = 6) in leukocytes for the components of interest. To improve precision, an internal standard was used for calibration. The limit of detection for all compounds is an absolute amount of 180 fmol, sufficient for the precise analysis of UDP-sugars in a limited amount of biological samples, such as human leukocytes (obtained from a 10 mL blood sample), muscle biopsies (< or = 100 mg), and mesangial kidney cells (ca. 2.5 x 10(5) cells). This reproducible, quantitative analysis of all four UDP-sugars from various biomedically relevant origins by CZE is a definite improvement over the generally used high performance liquid chromatography (HPLC) procedures. The CZE method allows the study of the flux through the hexosamine pathway in diabetes mellitus and other diseases in a simple, quantitative and accurate way.     

Molecular hydrogen in a-si:H

It is demonstrated that in high quality hydrogenated amorphous silicon films nearly 40% of the contained hydrogen is in the form of hydrogen molecules individually trapped in the amorphous equivalent of tetragonal T sites. The majority of these molecular hydrogens are in the less-clustered component of the contained hydrogen. These results could have major implications for the understanding of light-induced defects and hydrogen mobility.     

X-ray spectroscopy at PSI

Crystal spectroscopy of the X-rays of exotic atoms started with a series of experiments using transmission spectrometers. Experiments at lower energies were made possible by the development of reflection spectroscopy. The progress made is illustrated with a measurement of the pion mass and the determination of strong interaction effects in pionic hydrogen isotopes. Modern developments aim at a determination of the strong interaction width on the level of %. The way to reach this goal is presented and the limits of the method and possible future experiments are discussed. This revised version was published online in August 2006 with corrections to the Cover Date.     

Über die Einwirkung des alkoholischen Kalis auf den Isovaleraldehyd

Ohne ZusammenfassungIch nehme mit Freuden die Gelegenheit wahr, am Schlusse dieser Mittheilung meinem hochverehrten Lehrer, Herrn Hofrath Lieben, für das lebhafte Interesse, das er dieser Arbeit entgegenbrachte, und für die stete Förderung derselben mit Rath und That, meinen tiefgefühlten Dank auszusprechen.