Radically different : Contrary to previous proposals, the main reaction of the HO. radical with guanosine or 2′‐deoxyguanosine is the hydrogen abstraction from the NH2 moiety to give a guanyl radical. This radical, characterized by a broad band in the visible region (around 610 nm), undergoes tautomerization to the most stable isomer.
Highly active, selective, and stable : Highly ordered mesoporous carbon without deposition of metal particles catalyzes the oxidative dehydrogenation of ethyl benzene to styrene. A high activity and selectivity as well as long catalytic stability when compared with activated carbon, is observed from this catalyst.
Particle vs tube : The present paper systematically investigates a range of fundamental geometrical and structural features of TiO2 nanotube layers and their effect on the dye‐sensitized solar cell conversion efficiency, to deduce the most promising strategies for improvement. It is found that the performance of the cells strongly depends on the morphology and crystalline structure of the nanotubes.
Shape‐controlled catalysis : High‐quality Pt–Cu nanocubes with an average size of about 8 nm (see picture, scale bar=20 nm) were synthesized from a high‐temperature organic solution system in the presence of various capping ligands. These cubic Pt–Cu nanocrystals terminated with {100} facets demonstrated a superior catalytic activity towards methanol oxidation compared to similar sized Pt–Cu and Pt nanospheres.
Surfaces with purposes : The electroinitiated patterning of self‐assembled monolayers enables the fabrication of a variety of complex nanostructures (see picture). The possibilities offered by the introduction of chemical selectivity through the local generation of chemically active groups and subsequent derivatization are reviewed, with a focus on progress in this area of research over the last four years.
Tell your guests when it's time to go : When avidin caps are attached to biotinylated colloidal mesoporous silica, the four subunits of the protein avidin can each bind to a biotin moiety attached to the surface (see picture). The resulting material is a promising candidate for the design of smart detergents or drug‐delivery systems. The caps can be opened to release guest molecules by controlled enzymatic hydrolysis of the protein.
Fluoro power : In agreement with theoretical studies on α‐fluorocarbanions an X‐ray crystal structure shows the α‐fluorobis(phenylsulfonyl)methide anion adopts a pyramidal configuration (see picture). High‐level calculations and NMR spectroscopy studies demonstrate that electron‐withdrawing substituents play a crucial role in modulating the properties of bis(phenylsulfonyl)methide anions.
Fit for a king : Cationic complexes of GeII can be prepared by using crown ethers to stabilize and protect the germanium center. Three different crown ethers were employed: [12]crown‐4 (see structure, Ge teal, O red, C gray), [15]crown‐5, and [18]crown‐6. The structures of the cationic complexes depend on the cavity size of the crown ether and on the substituent on germanium.
Soluble short single‐walled carbon nanotubes in aerated D2O emit in the near‐infrared (NIR) region (see picture) with a quantum yield of (3.9±0.5) ×10?3 and a half‐life of 7.65 μs. This emission is quenched by electron‐ acceptor molecules.
Simple, versatile and green : Diels–Alder “click” chemistry is a simple, versatile and “greener” approach in the design of a diverse range of dendritic macromolecules (see scheme).
My favorite subject at school was Chemistry. I chose chemistry as a career because I love the fact we can “Just Do It” without over‐thinking. This and more about Wenbin Lin can be found on page 4472.
A DNA spin‐off : Electrospinning of DNA complexes gives nanofibers with a highly ordered morphology that allows homogeneous distribution of encapsulated multiple chromophores. The emission color can be controlled by suitable choice of the donor–acceptor pair and the doping ratio. Pure white‐light emission from nanofibers is demonstrated (see picture).
Hide and seek : The composition of a dynamic covalent equilibrium reaction is determined by measuring the ‘left‐over’ concentration of a reference compound (blue object, see picture). Reaction of the reference compound with a scavenger generates a characteristic UV/Vis signal that is independent of the molecular structure of the target.
DNA hybrid catalysis goes organometallic : A DNA strand functionalized with diene ligands forms iridium(I) complexes that can efficiently catalyze an allylic amination in aqueous medium (see scheme). The DNA‐based complexes show high stability and activity, and their secondary structure influences the stereoselectivity of the reaction.
