Silica scaffolding : By employing functionalized mesoporous SBA‐15 silica, novel fluorescent cruciform‐silica hybrid materials are generated which preserve the desirable solution properties of cruciforms in the solid state for potential use in sensory schemes.
Taking the air! A PdII‐catalyzed intramolecular hydroamination of allenes coupled to alcohol oxidation has been developed. This reaction is performed by using a nitrogen‐based ligand under aerobic conditions, under which the molecular oxygen is used as the terminal oxidant for the reoxidation of Pd0 species to complete the catalytic cycle.
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.
State‐of‐the‐art molecular‐beam techniques reveal that the lowest lying electronic excited state in purine is the nπ* state. Using multiphoton ionization spectroscopy, the origin is found to occur at 31 309 cm?1, and a vibrational structure is visible that is assigned to the skeletal motion of the ring (see figure).
Fun in the sun! A strategy has been devised for functionalizing and solubilizing boron dipyrromethene (Bodipy) dyes at the central boron atom and changing the color by increasing delocalization on the central core. This approach leads to the formation of stable B? C≡C and pyrrole? C?C linkages suitable for use in TiO2‐sensitized devices (see figure).
Constructing α‐stereogenic amides and ketones : The highly regioselective and enantioselective conjugate addition of 1,3‐dicarbonyl compounds to 1,4‐dicarbonyl but‐2‐enes has been developed with the chiral bicyclic guanidine as catalyst (ee values up to 97 %; see scheme).
Fast detection of cellular thiols in aqueous medium was achieved using a newly developed fluorescence probe (see picture). Based on this probe, a high‐throughput fluorescence assay for glutathione reductase was developed.
Dynamic duo : Magnetic resonance imaging (MRI) can visualize deep regions of living bodies, whereas fluorescence measurement offers excellent sensitivity. These methods thus offer signal enhancement potential for detecting enzyme activities. A dual‐mode off/on probe to detect caspase‐3 activity by fluorescence and 19F MRI is presented.
Just subtract water : Amphiphilic π‐conjugated acyclic oligopyrroles form solvent‐assisted H‐aggregates that give rise to vesicular structures in aqueous solution (see figure). The H‐aggregates are sensitive to the conditions and are transformed into J‐aggregates by the removal of water.
First insights into the reaction between a Baylis–Hillman adduct and an allene moiety have been obtained from the novel domino heterocyclization/cross‐coupling reaction of α‐allenols and Baylis–Hillman acetates, which furnishes [(2,5‐dihydrofuran‐3‐yl)methyl]acrylate derivatives in moderate to good yields.
Micropatterns of silica were generated under biocompatible conditions by a combination of microcontact printing (μCP), layer‐by‐layer (LbL) self‐assembly, and biomimetic silicification. Quaternary amine‐containing poly(diallyl dimethyl ammonium chloride) induced polycondensation of silicic acid, resulting in spatioselective formation of silica micropatterns. Scale bar: 10 μm.
To each his own : An addressable electrochemical device consisting of orthogonally arranged rows and columns of electrodes has been constructed to monitor protein expression in genetically engineered cells at the single‐cell level. The response based on redox cycling reflected the different expression levels of the enzyme from individual HeLa cells transfected with a plasmid vector including secreted alkaline phosphatase.
A black whole : The black insoluble biopolymer eumelanin is prepared through the oxidative polymerization of 5,6‐dihydroxyindoles (see scheme). It has a largely unknown heterogeneous structure and unique optoelectronic properties. Current structural models are presented and possible applications are discussed.
