Different lights, different selectivies : Luminescence of a new guanidinium 3,3′‐functionalized bipyridyl–RuII complex has been studied for sensing of several anions. L ‐Glutamate and dihydrogenphosphate are both detected by photoluminescence and electrochemiluminescence. However, the complex displays differential selectivities for these anions depending on the sensing channels (see scheme).
Pinches like a crab : The utilization of guanidines as catalysts has been growing at a steady pace. They possess high pKa values and activate through dual hydrogen‐bonding modes of activation. This Focus Review highlights the development of chiral guanidine catalysts in asymmetric organic transformations.
Making circles with N and O : Cyclic tripeptides containing an unnatural Cα‐tetrasubstituted THF amino acid are prepared by copper(I) and palladium(0)‐catalyzed N‐ and O‐arylation reactions. The reactions give access to side chain‐modified derivatives of the unnatural amino acid and macrocyclic peptidomimetics.
In‐source oxidation : In‐source photocatalytic redox reactions for inducing peptide fragmentation are achieved on a TiO2‐derived target plate during laser desorption ionization mass spectrometry in the presence of samples and glucose acting as both an electron donor and a hole conductor (see scheme).
An efficient mechanism for the sequence‐specific inhibition of gene expression is RNA interference. In this process, double‐stranded RNA molecules induce cleavage of a selected target RNA (see picture). This technique has in recent years developed into a standard method of molecular biology. Successful applications in animal models have already led to the initiation of RNAi‐based clinical trials as a new therapeutic option.
Large aqueous oxide ions as minerals! Minerals dissolve by repeated ligand exchange reactions and geochemists use polyoxometalate ions to establish structure–reactivity relations for environmentally important functional groups. Here, for example, are plotted the dissolution rates of two classes of minerals against rates of solvent exchanges around the corresponding aquo ions.
Uniform nanodonuts: Stable toroidal micelles that have a highly uniform size and shape spontaneously self‐assemble from a selective THF/ethanol solvent mixture (see 3D AFM image). The donut‐shaped micelles can be used as a template to grow gold nanoparticles, which form along the ring surface.
Perfluorination: The fully fluorinated analogue of pentaphenylborole (see structure; B gray, C black, F green) has been prepared using successive transmetallation reactions involving Zr and Sn heterocycles. The highly moisture‐sensitive borole is a new member of the perfluoroaryl borane family, a class of antiaromatic compounds of fundamental significance to concepts of aromaticity.
Artificial biolumiscence : The use of a supramolecular hydrogel to confine heme proteins and luminol can enhance the quantum yield of chemiluminescence (CL) by about an order of magnitude and give an emission time 4–6 times longer.
