Easy and direct : Regioselective Mizoroki–Heck‐coupling reactions using heteroaromatic tosylates as electrophiles were achieved, thus providing direct and easy access to highly functionalized α‐heteroarylvinyl amides and ethers.
An N for Ir : The synthesis and X‐ray crystal structure of a late‐transition‐metal complex with a terminal nitrido ligand and its hydrogenation to the related amido complex are reported (see scheme).
Spot the difference : The five‐coordinate iron(II) cyanoporphyrinates, which are spin‐crossover compounds, can be used to synthesize previously unknown six‐coordinate complexes. Bis(cyano) and (cyano)imidazole complexes are presented, and the five‐ and six‐coordinate (cyano)iron(II) derivatives are compared with analogous CO complexes.
Kept in the dark : The non‐photocatalytic generation of free radicals from fine and ultrafine TiO2 particles has been studied by means of a spin‐trapping/ESR spectroscopy technique (see figure). The amount and kind of free radicals generated depends on the crystalline structure, but not on the particle dimensions.
Traffic control : By exploiting the interplay of kinetic and thermodynamic effects, the direction of threading/dethreading in a nonsymmetric calixarene wheel can be selected by an appropriate choice of the head group incorporated in the molecular axle (see figure).
Rings around a ring : The synthesis, characterization, material properties and biological studies of novel hexakis porphyrinato cyclotriphosphazene systems (see scheme) and their metal derivatives are described.
Recycling of “green” solvents : Recycling of ionic liquids with high efficiency is of key importance on going from the laboratory‐scale to large‐scale industrial application of these solvents.
Sharp curves : The structure of a locked nucleic acid modified telomeric sequence from Oxytricha nova displays a remarkable folding topology, distinct from the native O. nova quadruplex. Each guanine stretch folds back in a V‐shaped turn that puts the first and fourth guanines in the same tetrad, looping over a tetrad with a sharp turn in the DNA backbone, showing how subtle interplay between sequence and conformation defines the folding topology.
Nice and easy : A very simple synthesis for dibenzopentalenes, which starts from 1‐bromo‐2‐ethynylbenzenes, has been developed. It uses Ni0 complexes (see scheme), from which a relatively stable NiII complex as an important intermediate has been isolated. Dibenzopentalenes with various functional groups can be prepared by the procedure, and their electronic properties are consistent with theoretical calculations.
In quarantine : Nitroxide spin probes are encapsulated by hexameric resorcinarene molecular capsules in dichloromethane solutions (see picture). A substantial reduction in the tumbling rates occurs upon encapsulation of two cationic probes and one neutral probe. As the molecular volume of the probe increases, the tumbling rate of the probe reflects the overall tumbling rate of the entire supramolecular assembly.
Lighting‐up time : A cation‐exchange reaction releases thousands of divalent cations from nonfluorescent CdSe ionic crystals and triggers fluorescence from thousands of originally nonfluorescent Fluo‐4 fluorophores to obtain a large fluorescence amplification (see picture) and a low detection limit in bioassays. The technique is fast, simple, with a large dye‐to‐reporter labeling ratio, and flexible in selection of nanocrystals and fluorophores.
Efficient at room temperature : The Au complex generated in situ from [(IPr)AuCl] and AgSbF6 promotes the [4C+3C] intramolecular cycloaddition of allenes and dienes at room temperature, and in a particularly efficient and versatile manner. A DFT study on dimethylallenyl precursors agreed with the formation and cycloaddition of a metal–allyl cation intermediate, and points to the 1,2‐hydride shift as the key rate‐limiting step.
