Reversed photoresponse: Indium tin oxide (ITO)/Au nanoparticle (NP)/TiO2 electrodes (see picture) exhibit cathodic photocurrents and positive photopotentials under visible light, whereas ITO/TiO2/Au NP electrodes show an inverted response. This behavior indicates that electron transfer occurs from the plasmon‐excited Au NPs to the TiO2 film. An enhanced O2 photoreduction activity is found for ITO/Au NP/TiO2/Pt electrodes.
Shifts for crystals : Solid‐state NMR spectroscopy can be used for structure determination of microcrystalline paramagnetic solids at natural isotopic abundance. The protocol makes use of paramagnetic effects, measured on suitably recorded 1H NMR spectra, to define the conformation of a molecule in the lattice and the intermolecular packing in the solid phase. The method is illustrated with a family of lanthanide compounds (see picture).
A trap that closes with a “click” : The copper‐catalyzed azide–alkyne cycloaddition can occur in different G‐quadruplex structures (see scheme). The species trapped by the click reaction can then be separated and analyzed. By using this approach, a DNA–RNA hybrid‐type G‐quadruplex structure formed by human telomeric DNA and RNA sequences was detected.
Weak and robust ? Tetraalkylammonium salts of weakly coordinating fluorinated alkoxyaluminates are easily accessible, chemically robust materials that show interesting physico‐chemical properties like low melting points, high electrochemical stability and electric conductivity in weakly polar solvents such as CH2Cl2, Ph‐F and toluene.
Selective HCOOH decomposition to H 2 /CO 2 on Au : Au species catalyze HCOOH dehydrogenation at higher rates than on Pt, previously considered the most active metal. Dehydrogenation occurs through formate decomposition limited by H2 desorption on Au species undetectable by TEM. CO did not form (<10 ppm), making products suitable for low‐temperature fuel cells.
Macrocyclic oxocarbenium ions can be formed from macrolactones that contain benzylic or allylic ether groups through oxidative carbon–hydrogen‐bond activation mediated by 2,3‐dichloro‐4,5‐dicyanoquinone (DDQ). The applicability of this efficient reaction to complex‐molecule synthesis was demonstrated by its use in a brief formal synthesis of neopeltolide (see retrosynthetic scheme) to form the tetrahydropyrone ring.
Fruity electrodes : A simple bottom‐up self‐assembly method was used to fabricate rambutan‐like tin–carbon (Sn@C) nanoarchitecture (see scheme, green Sn) to improve the reversible storage of lithium in tin. The mechanism of the growth of the pear‐like hairs is explored.
Bringing order : A new class of periodic mesoporous organosilicas (PMOs) with a urea‐bridged organosilica precursor under acid‐catalyzed and inorganic‐salt‐assisted conditions was obtained. The large‐pore hybrid materials have ordered mesostructure with uniform pore size distributions, which can be seen from the TEM images.
Nanocrystalline TiO 2 (anatase) is an essential oxide for environment and energy applications. A combination of EXAFS spectroscopy and DFT calculations on a series of dopants with quite similar ion radius, but increasing ion charge, show boundary space charge segregation of acceptor cations. The picture illustrates the Fourier‐transformed EXAFS spectrum for Sn4+‐doped TiO2.
Fullerene flakes : A diacetylene‐functionalized fullerene derivative self‐organizes into flakelike microparticles (see picture). Both the diacetylene and C60 moieties can be effectively cross‐linked, which leads to supramolecular materials with remarkable resistivity to solvent, heat, and mechanical stress. Moreover, the surface of the cross‐linked flakelike objects is highly durable and water‐repellent.
Bleomycin mimics : Efficient oxidative double‐strand DNA cleavage has been achieved with multinuclear non‐heme iron complexes (see scheme). These complexes therefore represent model compounds that mimic the mode of action of the anti‐tumor drug bleomycin.
The center of it all : An antitumor‐active trinuclear platinum complex forms unprecedented interstrand cross‐linked triadducts with 18‐mer DNA duplexes (see figure; complex in yellow with the platinum centers in red) and behaves differently from its dinuclear analogue.
Molecular organization : Chiral benzene tricarboxamides with methyl substituents at defined positions self‐assemble into supramolecular polymers of preferred helicity by three‐fold α‐helical‐type hydrogen bonding. The odd–even effect is operative and all derivatives are liquid crystalline showing a Colho phase (see figure).
The stereogenic centers at C3 and C12 of meloscine ( 3 ) can be established in the photochemical key step 1 → 2 . 1,2‐retro‐Benzilic acid rearrangement to a five‐membered ring, reductive amination, Claisen rearrangement, and ring‐closing metathesis are further key steps in the transformation of cyclobutane 2 into the target molecule 3 (14 steps, 9 % overall yield). Enantioselective access to (+)‐meloscine was possible when the [2+2]‐photocycloaddition was conducted in the presence of a chiral template.
