Effects of FeCl3 as oxidizing agent on the conduction mechanisms in polypyrrole (PPy)/pc–ZnO hybrid heterojunctions grown by oxidative chemical vapor deposition

P‐type polypyrrole (PPy) films are deposited on glass and on n‐type polycrystalline ZnO (pc–ZnO) substrates by oxidative chemical vapor deposition under three different amounts of FeCl₃ used as oxidizing agents to form hybrid heterojunctions. Their microstructure, morphology, and electrical characteristics are studied. Particularly, current–voltage characteristics of the PPy/pc–ZnO heterojunctions are analyzed by defining an electrical equivalent circuit. The extracted parameters, together with the estimated heterojunction barrier height and the HOMO energy level of the PPy, indicate that a thermionic emission of holes at the heterojunction determines the saturation current of the diode at low voltage. For larger FeCl₃ amounts, the diode ideality factor increases indicating an increment of recombination by tunneling of charge carriers occurring at the heterojunction. This is attributed to a narrowing of the space charge region due to an increment of the number of charge carriers with a growing amount of FeCl₃. At high voltages, the PPy thickness influences the ohmic and space–charge limited current mechanisms at the bulk region. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1537–1544     

Dinitrogen Splitting Coupled to Protonation

The coupling of electron- and proton-transfer steps provides a general concept to control the driving force of redox reactions. N₂ splitting of a molybdenum dinitrogen complex into nitrides coupled to a reaction with Brønsted acid is reported. Remarkably, our spectroscopic, kinetic, and computational mechanistic analysis attributes N−N bond cleavage to protonation in the periphery of an amide pincer ligands rather than the {Mo−N₂−Mo} core. The strong effect on electronic structure and ultimately the thermochemistry and kinetic barrier of N−N bond cleavage is an unusual case of a proton-coupled metal-to-ligand charge transfer process, highlighting the use of proton-responsive ligands for nitrogen fixation.     

Über die Oxydationsproducte der Palmitinsäure mit Kaliumpermanganat in alkalischer Lösung

Ohne Zusammenfassung     

Visual DNA as a diagnostic tool

We report on the incorporation of the Visual DNA concept in a genotyping assay as a simple and straightforward detection tool. The principle of trapping streptavidin‐coated superparamagnetic beads of micrometer size for visualization of genetic variances is used for PrASE‐based detection of a panel of mutations in the severe and common genetic disorder of cystic fibrosis. The method allows a final investigation of genotypes by the naked eye and the output is easily documented using a regular hand‐held device with an integrated digital camera. A number of samples were run through the assay, showing rapid and accurate detection using superparamagnetic beads and an off‐the‐shelf neodymium magnet. The assay emphasizes the power of Visual DNA and demonstrates the potential value of the method in future point‐of‐care tests.