Vanadium Alumanyl Complex: Synthesis, Characterization, Reactivity, and Application as a Catalyst for C-H Alumanylation of Alkenes.

A complex containing a V-Al bond is described. This species can be prepared by either transmetalation of a previously disclosed alumanylpotassium with Cp2VCl or photolytic oxidative alumination of Cp2V using the corresponding dialumane. Reaction of the resulting V-Al complex with H2 gave a Cp2V-dihydridoaluminate complex. These complexes were studied with X-ray crystallography, vanadium K-edge XANES spectroscopy, and DFT calculations. Finally, the reactivity of these molecules was studied opening the way to a catalytic C-H alumanylation of alkenes.

Mechanochemical Synthesis of Non-Solvated Dialkylalumanyl Anion and XPS Characterization of Al(I) and Al(II) Species.

A non-solvated alkyl-substituted Al(I) anion dimer was synthesized by a reduction of haloalumane precursor using a mechanochemical method. The crystallographic and theoretical analysis revealed its structure and electronic properties. Experimental XPS analysis of the Al(I) anions with reference compounds revealed the lower Al 2p binding energy corresponds to the lower oxidation state of Al species. It should be emphasized that the experimentally obtained XPS binding energies were reproduced by delta SCF calculations and were linearly correlated with NPA charges and 2p orbital energies.

Finding Oxygen Reservoir by Using Extremely Small Test Cell Structure for Resistive Random Access Memory with Replaceable Bottom Electrode.

Although the presence of an oxygen reservoir (OR) is assumed in many models that explain resistive switching of resistive random access memory (ReRAM) with electrode/metal oxide (MO)/electrode structures, the location of OR is not clear. We have previously reported a method, which involved the use of an AFM cantilever, for preparing an extremely small ReRAM cell that has a removable bottom electrode (BE). In this study, we used this cell structure to specify the location of OR. Because an anode is often assumed to work as OR, we investigated the effect of changing anodes without changing the MO layer and the cathode on the occurrence of reset. It was found that the reset occurred independently of the catalytic ability and Gibbs free energy (ΔG) of the anode. Our proposed structure enabled to determine that the reset was caused by repairing oxygen vacancies of which a filament consists due to the migration of oxygen ions from the surrounding area when high ΔG anode metal is used, whereas by oxidizing the anode due to the migration of oxygen ions from the MO layer when low ΔG anode metal is used, suggesting the location of OR depends on ΔG of the anode.