Reduktionsgrad in Photoredox-Systemen

Reduction Degree in Photoredox-Systems The reduction degree is in many photoredox systems an invariant under irradiation. Therefore it represents an important degree of freedom in these systems. It is possible to define the reduction degree in such a systematic way, that it may also be applied for discussing complicated systems. It would be helpful to have selective electrode material for the examination of photoredox systems. We have succeeded in finding a selective electrode material for the iron in the iron/thionin system as well as in the iron/iodine system.     

Depth profile studies of ZrTiN coatings by laser ablation inductively coupled plasma mass spectrometry

The feasibility of depth profiling was studied by using a 193-nm ArF* excimer laser ablation system (GeoLas, MicroLas, Goettingen, Germany) with a lens array-based beam homogenizer in combination with an ICP-QMS Agilent 7500. Two ablation cells (20 and 1.5 cm³) were compared at the laser repetition rate of 1 Hz, laser beam energy of 135 mJ and the carrier gas flow rate 1.5 L min^–1 He + 0.78 L min^–1 Ar. The ablation cell dimensions are important parameters for signal tailing; however, very small cell volumes (e.g. 1.5 cm³) may cause memory effects, which can be probably explained by dominant inertial losses of aerosol on cell walls with its delayed mobilization. The 20-cm³ ablation cell seems to be appropriate for depth profiling by continuous single-hole drilling. The study of the influence of the pit diameter magnitude on the waning and emerging signals under small crater depth/diameter aspect ratios, which range between 0.75 and 0.0375 for the 3-m-thick coatings and pit diameters 4–80 m, revealed that the steady-state signals of pure coating and pure substrate (out of interface) were obtained at crater diameters between 20 and 40 m. Depth resolution defined by means of slopes of tangents in the layer interface region depend on the pit diameter and has an optimum value between 20 and 40 m and gives 0.6 m for the 20-m pit. In-depth variation of concentration of coating constituent (Ti) was proved to be almost identical with two different laser/ICP systems.Viktor Kanický performed this work while on leave at ETH Zurich     

Clickosomes--using triazole-linked phospholipid connectors to fuse vesicles

Two complementary artificial diether phospholipids were synthesized that can undergo a Cu(I)-catalyzed Huisgen-Sharpless click reaction. The resulting lipid can bridge the membranes of large unilamellar vesicles and cause their aggregation and ultimately their fusion.     

FIR.-Spektren von Übergangsmetallkomplexen mit orthogonalem Ligandensystem. I. Halogeno-Kupfer(II)-Komplexe methylsubstituierter Pyridine

Far-infrared spectra (400–40 cm^?1) have been studied for orthogonal systems CuL₂X₂ (L = pyridine, mono-, di-, tri-methylsubstituted pyridine and X = Cl, Br). Assignements are suggested for the four bands of the molecular vibrations which form a stable region within the spectra of the complex series. Relations between number and position of bands and structural data are discussed.     

Ion-Selective Sensors

Numerous advances have recently been made in the development of ion-selective (glass, solid, liquid) membrane electrode systems. The theoretical principles and practical requirements of such “sensors” are outlined in this article, and an attempt is made to review their possible applications.     

Cyclosporin A,ein immunsuppressiv wirksamer Peptidmetabolit aus Trichoderma polysporum (LINK ex PERS.) Rifai

Cyclosporin A, a Peptide Metabolite from Trichoderma polysporum (LINK ex PERS .) Rifai, with a remarkable immunosuppressive activity Two antifungal metabolites, cyclosporins A and C, were isolated from a strain of Trichoderma polysporum (LINK ex PERS .) Rifai. Cyclosporin A, the main component, has the molecular formula C₆₂H₁₁₁N₁₁O₁₂ as deduced by NMR. and mass spectra. Hydrolytic cleavage of cyclosporin A furnished 11 amino acids as fragments, among them an artefact of a new C₉-amino acid. The amino acid sequence was determined by Edman degradation of iso-cyclosporin A, a basic rearrangement product formed from cyclosporin A by N, O-acyl migration. In an independent investigation an X-ray analysis of the iodo derivative 10 was performed (see the following paper). On the basis of the chemical, spectroscopic and crystallographic evidence the complete structure of cyclosporin A was elucidated as the neutral cyclic oligopeptide 1 . Cyclosporin A and C show remarkable immunosuppressive and antiphlogistic activities in several pharmacological models.