Guest Effect : The differences of nitrogen atom positions and the bridge bonds linked to two pyridine rings of some bipyridine guests can significantly affect the binding abilities and inclusion geometries of β‐cyclodextrin with the guests in both the solution and solid states.
Positive discrimination : Chemo‐ and regioselective palladium‐catalyzed cycloetherification of allendiols, namely β,γ‐ and γ,δ‐allendiols, may occur by judicious choice of palladium‐catalyzed conditions owing to their potential ability to discriminate between both nucleophilic sites (see scheme).
Codeposition of NO and O 2 diluted in Ne at 6 K yield a ON???OO complex that exhibit strong UV absorption. This complex is converted into NO3 radicals by UV irradiation, and is regenerated by radiation of visible light (see spectra).
Basic catalysis! The basic properties of hydrotalcites (see picture) make them attractive for numerous catalytic applications. Probing the basicity of the catalysts is crucial to understand the base‐catalysed processes and to optimise the catalyst preparation. Various parameters can be employed to tune the basic properties of hydrotalcite‐based catalysts towards the basicity demanded by each target chemical reaction.
Awakening of the Cp one : The bifunctional complex 1 facilitates the interaction with substrates bearing less electrophilic carbon atoms than ketones, epoxides, and imides. The title reaction was applicable to the reduction of Evans' asymmetric alkylation products to the chiral alcohols along with good recovery of the chiral oxazolidinone auxiliary. EWG=electron‐withdrawing group.
Quick on the uptake : A multiscale theoretical method predicts that the gravimetric adsorption capacities of H2 in Li‐doped covalent organic frameworks based on the building blocks shown (Li violet, H white, B pink, C green, O red, Si yellow) can reach nearly 7 % at T=298 K and p=100 bar, suggesting that these Li‐doped materials are promising adsorbents for hydrogen storage.
Osmabenzenes can be easily synthesized from two η2‐coordinated olefin osmacycles in the presence of benzonitrile by means of facile hydrogen‐transfer conversions (see graphic). Mechanisms for the formation of osmabenzenes are proposed based on DFT calculations.
Magnesium‐doped GaN nanowires with different dopant concentrations are synthesized and their morphology, structure, growth properties, crystallinity, and optical properties investigated. The nanowires are single‐crystalline with hexagonal wurzite structure, and doping with 5 atom % of Mg gives nanowires with the best morphology and crystallinity (see HRTEM image).
Cancer‐cell‐targeted gene silencing was observed with a magnetic‐nanoparticle platform (MEIO, magnetism‐engineered iron oxide) on which a fluorescent dye, siRNA, and a RGD‐peptide targeting moiety were attached (see picture). The different functionalities enable the macroscopic (magnetic resonance) and microscopic (fluorescence) imaging of target cells. This system may be suitable for concurrent diagnostic and therapeutic applications.
Retained : An N‐heterocyclic carbene with eight cyclohexyl groups (see figure) provides increased electron density for a highly active olefin metathesis catalyst as well as sufficient steric bulk to allow the efficient separation of such a complex from the organic products in the solvent‐resistant nanofiltration.
Covalent, ionic, or something new? A new interpretation of the topology of the electron density at the bond critical point is proposed to characterize covalent, ionic, and charge‐shift bonding from the density point of view (see figure). The topological properties of the density representation confirm the reality of charge‐shift bonds, in which the covalent contribution is weak or repulsive, and most of the bonding is due to the covalent–ionic resonance energy.
