A family of heterobimetallic cubes shows spin-crossover behaviour near room temperature

Using 4-(4′-pyridyl)aniline as a simple organic building block in combination with three different aldehyde components together with metal(II) salts gave three different Fe8Pt6-cubes and their corresponding Zn8Pt6 analogues by employing the subcomponent self-assembly approach. Whereas the use of zinc(II) salts gave rise to diamagnetic cages, iron(II) salts yielded metallosupramolecular cages that show spin-crossover behaviour in solution. The spin-transition temperature T1/2 depends on the incorporated aldehyde component, giving a construction kit for the deliberate synthesis of spin-crossover compounds with tailored transition properties. Incorporation of 4-thiazolecarbaldehyde or N-methyl-2-imidazole-carbaldehyde yielded cages that undergo spin-crossover around room temperature whereas the cage obtained using 1H-4-imidazolecarbaldehyde shows a spin-transition at low temperatures. Three new structures were characterized by synchrotron X-ray diffraction and all structures were characterized by mass spectrometry, NMR and UV/Vis spectroscopy

Formkörper, mechanische Eigenschaften und Verbundswerkstoffe amorpher Si/B/N/C-Keramiken sowie Studien zur Synthese von Phosphorcarbiden über Precursorrouten

Amorphe Keramiken des Systems Si/B/N/C sind aufgrund ihrer hervorragenden mechanischen, chemischen und thermischen Eigenschaften von hohem Interesse. Ihre Anwendung war bislang jedoch auf die Herstellung von Fasern oder Beschichtungen beschränkt. Diese Arbeit liefert nun Beiträge zur weiteren Werkstoffanwendung dieser Verbindungsklasse, indem neue Routen zu kompakten, makroskopischen und dreidimensionalen Bauteilen präsentiert werden. Hierzu werden Herstellungswege für monolithische Formkörper, Mikrokomposite und Faser-Matrix-Verbundstoffe vorgestellt. Darüber hinaus wird im System Phosphor/Kohlenstoff, in dem bislang keine binären Verbindungen bekannt waren, die Synthese eines amorphen Phosphorcarbids mit der Zusammensetzung P2C6 aufgezeigt

der Rheinischen Friedrich-Wilhelms-Universität Bonn

der Rheinischen Friedrich-Wilhelms-Universität Bonn vorgelegt vo

A Family of Heterobimetallic Cubes Shows Spin‐Crossover Behaviour Near Room Temperature

Using 4-(4′-pyridyl)aniline as a simple organic building block in combination with three different aldehyde components together with metal(II) salts gave three different Fe8Pt6-cubes and their corresponding Zn$_8$Pt$_6$ analogues by employing the subcomponent self-assembly approach. Whereas the use of zinc(II) salts gave rise to diamagnetic cages, iron(II) salts yielded metallosupramolecular cages that show spin-crossover behaviour in solution. The spin-transition temperature T$_{1/2}$ depends on the incorporated aldehyde component, giving a construction kit for the deliberate synthesis of spin-crossover compounds with tailored transition properties. Incorporation of 4-thiazolecarbaldehyde or N-methyl-2-imidazole-carbaldehyde yielded cages that undergo spin-crossover around room temperature whereas the cage obtained using 1H-4-imidazolecarbaldehyde shows a spin-transition at low temperatures. Three new structures were characterized by synchrotron X-ray diffraction and all structures were characterized by mass spectrometry, NMR and UV/Vis spectroscopy