Abstract This communication gives an overview of the relationships between four reactions that although related were not always perceived as such: S N 2, Walden, Finkelstein, and Menshutkin. Binary interactions (S 2 & Menshutkin, Walden Menshutkin Finkelstein) reported. Carbon, silicon, nitrogen, phosphorus central atoms fluorides, chlorides, bromides, iodides lateral considered. Theoretica...

Time-resolved extinction spectroscopy is employed to study the reaction kinetics in the shape-conversion reaction involving halide ions (including Cl(-), Br(-) and I(-)) etching (sculpturing) silver nanoplates. A series of time-resolved extinction spectra are obtained during the in situ etching process and the evolution of surface plasmon resonance (SPR) of the silver nanoparticles is analyzed....

We report a facile halide ion (Cl(-) or Br(-)) mediated synthesis of Fe nanoparticles (NPs) by thermal decomposition of Fe(CO)5. The NP structure is controlled to be either amorphous (in the absence of halide ions) or single crystalline bcc (in the presence of halide ions). Through systematic investigation on the synthetic conditions, we have confirmed that the formation of bcc-Fe NPs is facili...

During the synthesis of SiC, Si3N 4 and sialon whiskers by carbothermal reduction of SiO 2, a localized formation of amorphous phases or Si2N20 powders was observed beneath these whiskers. Because these whiskers were formed by the vapour/solid mechanism, the controlling gas phase was of primary importance to obtain whiskers of tailored morphology and chemistry. To elucidate the effect of the ga...

The concept of the mineral classification in the Mineral Powder Diffraction File (MPDF) is somewhat different from that used in classical mineralogical references. The goal of the classification is to exploit the crystal chemistry characteristics to the fullest to assist in the identification of mineral phases. The primary criterion is the similarity of the diffraction pattern, which results fr...

Following pioneering works, the 3D hybrid lead-halide perovskites CH3NH3PbX3 (X=Cl, Br, I) have recently been shown to drastically improve the efficiency of Dye Sensitized Solar Cells (DSSC). It is predicted to open “a new era and a new avenue of research and development for low-cost solar cells ... likely to push the absolute power conversion efficiency toward that of CIGS (20%) and then towar...

Nanocrystalline cesium lead halide perovskites (CsPbX3, X = Cl, Br, and I) form an exciting new class of semiconductor materials showing quantum confinement. The emission color can be tuned over the full visible spectral region making them promising for light‒emitting applications. Further control over the optical and magnetic properties of quantum dots (QDs) can be achieved through doping of t...

The molecular chemistry of the f-elements, i.e. the lanthanides and actinides, is traditionally dominated by the use of carbon, nitrogen, oxygen or halide ligands. However, the use of metal-based fragments as ligands is underdeveloped, which contrasts to the field of d-block metal–metal complexes that have developed extensively over the last 50 years. Consequently, the use of metal-based fragme...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

Controlling the size and shape of semiconducting nanocrystals advances nanoelectronics and photonics. Quantum-confined, inexpensive, solution-derived metal halide perovskites offer narrowband, color-pure emitters as integral parts of next-generation displays and optoelectronic devices. We use nanoporous silicon and alumina thin films as templates for the growth of perovskite nanocrystallites di...