Coexistence of 3d‐Ferromagnetism and Superconductivity in [(Li1−xFex)OH](Fe1−yLiy)Se

Superconducting [(Li_1?xFe_x)OH](Fe_1?yLi_y)Se (x≈0.2, y≈0.08) was synthesized by hydrothermal methods and characterized by single‐crystal and powder X‐ray diffraction. The structure contains alternating layers of anti‐PbO type (Fe_1?yLi_y)Se and (Li_1?xFe_x)OH. Electrical resistivity and magnetic susceptibility measurements reveal superconductivity at 43 K. An anomaly in the diamagnetic shielding indicates ferromagnetic ordering near 10 K while superconductivity is retained. The ferromagnetism is from the iron atoms in the (Li_1?xFe_x)OH layer. Isothermal magnetization measurements confirm the superposition of ferromagnetic and superconducting hysteresis. The internal ferromagnetic field is larger than the lower, but smaller than the upper critical field of the superconductor. The formation of a spontaneous vortex phase where both orders coexist is supported by ⁵⁷Fe‐Mössbauer spectra, ⁷Li‐NMR spectra, and μSR experiments.     

Living cationic polymerization of vinyl ethers

The cationic polymerization of vinyl ethers initiated by CH₃-CH(OR)(I) / R₄N⁺A⁻ (R = Alkyl, A⁻ = ClO₄⁻, BF₄⁻, PF₆⁻, I⁻, NO₃⁻) shows the characteristics of a living polymerization. The rate of polymerization is a function of the solvent polarity, the temperature, the type and concentration of the ammonium salt. The experimental data can be explained on the basis of the secondary salt effect overlapped by some dipol-dipol interactions of the chain end and the added salt. Functionalization of the chain end with thermolabile azo functions yields polymeric initiator which was applied for the synthesis of blockcopolymers. Vinyl ethers functionalized with furylacrylic ester groups were polymerized and crosslinked via [2+2] cycloaddition.     

Meßanordnung zur X-γ-Koinzidenzspektrometrie geringer Aktivitäten von Elektroneneinfangstrahlern

Durch Anwendung der X-γ-Koinzidenzspektrometric wird die Nachweisgrenze im Vergleich zur einfachen γ-Spektrometrie für die meisten Elektroneneinfangstrahler verbessert. Die beschriebene Meβanordnung ist zur Messung geringer Aktivitäten von Elektroneneinfangstrahlern mit Z ≧ 30 geeignet.     

Palladium complexes of unsymmetrical 1,3-bis(aryliminio)isoindoline (BAI) ligands: A novel class of complexes exhibiting unusual structural features

The metallation of two homologous, unsymmetrical BAI (1,3-bis(aryliminio)isoindoline) ligands with palladium acetate leads to square–planar cyclometallated Pd^II complexes, comprising a C–H bond activated dianionic and tetradentate BAI ligand. In the solid state these isostructural monomeric complexes form a structural motif containing large voids, despite the absence of other than dispersive intermolecular interactions.