Through a glass darkly : Several recent autocatalytic reaction models for the origin of homochirality have suggested ways in which one enantiomer of the product might be reconverted into the other by a recycling reaction in a closed system. These models are revealed to violate the principle of microscopic reversibility, a powerful tool for assessing the plausibility of proposed reaction networks even at far‐from‐equilibrium conditions.
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).
SERS you right: The plasmon heating of gold nanoshells is exploited to yield the local conversion of amorphous TiO2 into anatase on the surface of polymeric colloidal crystals (see scheme). The resulting Au/TiO2 spots are active substrates for surface‐enhanced Raman spectroscopy and allow surface reactions and processes to be followed directly on‐site.
Keeping their cool : Fabrication of a 2D weblike nanonetwork of gold was successfully demonstrated through a two‐step procedure including complexation of gold precursors to a weblike supramolecular assembly of surfactant followed by in situ reduction of the precursors to gold. Molecular assemblies stabilized by hydrogen bonding provided a sound template, leading to the highly integrated structure of gold through room‐temperature (cold) nanostructure fusion.
Size is not all! Investigation of the controlled release of tertiary alcohols from the surface of dendrimers and “stylomers” as polymer model systems (see scheme) showed that the polarity of the conjugates and structural modifications in close proximity to the release unit have a stronger influence on the rates of hydrolysis than the size (generation) or shape (linear or spherical) of the macromolecules.
Exciton migration! Spectroscopic analyses and extensive molecular dynamics studies revealed a well‐defined 41 helix in which the perylene molecules (see figure) form four “helter‐skelter‐like” overlapping pathways along which excitons and electrons can rapidly migrate.
Dendrimers for ion sensing : The synthesis and use of new tris‐alkynyl dendrons are reported. So‐called “click” reactions of the dendrimers described with azidomethylferrocene give 27‐ferrocenyl, 81‐ferrocenyl, and 243‐ferrocenyl dendrimers. Electrochemical recognition of oxo‐anions and Pd2+ cations has been compared using the three polyferrocenyl dendrimers.
In a new light : The NADPH:protochlorophyllide (Pchlide) oxidoreductase (POR; see structure, green Pchlide, yellow NADPH) is a good model to investigate catalytical processes in enzymes, as its light activation allows an immediate start of the catalyzed reaction. By irradiation with weak, short laser pulses it is possible to detect conformation changes during the reaction and thus to uncover the elementary steps of the catalytic process.
Electrode‐dependent potential windows (see picture, GC=glassy carbon) are determined for five dialkylammonium carbamate (dialcarb) room‐temperature ionic liquids in a systematic study of their physical and electrochemical properties. The viscosity and conductivity of the dialcarb ionic liquids, which are “distillable” at low temperature, are comparable to those of some conventional room‐temperature ionic liquids.
One catalyst, many materials : The chemistry of polyolefins has been thoroughly explored, and it sometimes seems as if any given polymer structure can be obtained by derivatization of the coordination catalyst. But this one catalyst, one material concept is self‐limiting. Recently introduced bimolecular group‐transfer reactions make a wide range of polyolefin materials accessible from a single catalyst by simple variation of reaction parameters.
Te for two : Supported by pyridine‐ or carbene‐based ligands, tellurium‐centered dications are prepared in high yield and include a dicationic tellurium analogue of the recently synthesized “carbodicarbene”. The key to accessing these compounds is the isolation of a base‐stabilized form of TeOTf2 (see structure), a new highly electrophilic reagent for tellurium chemistry.
Quick access : A concise and efficient formal synthesis of platencin has been accomplished in nine steps from a commercially available starting material. The synthesis utilized only one protecting group. The base‐catalyzed Michael cyclization of precursor 1 afforded the key diketone 2 , which was converted into the desired core structure 4 via the radical intermediate 3 .
Positive discrimination : Chemo‐ and regioselective palladium‐catalyzed cycloetherification of allendiols, namely β,γ‐ and γ,δ‐allendiols, may occur by judicious choice of palladium‐catalyzed conditions owing to their potential ability to discriminate between both nucleophilic sites (see scheme).
Spinning wheels : The presented highly resolved multifrequency continuous wave EPR spectra (e.g., see figure) of the heterooctametalic “wheels” Cr7M provide rare examples of high nuclearity polymetallic systems where detailed information on the spin‐Hamiltonian parameters of the ground and excited spin states is observed.
Supramolecular chirality and liquid crystalline OFET : Achiral end‐capped oligothiophenes can be tuned to exhibit supramolecular chirality with unique striped textures showing distinct circular dichroism signals as well as a highly ordered SmE phase that leads to high hole carrier mobility.
Breathe easy : Reversible H2O and NH3 gas uptake by 2D calcium tetraphosphonates (see figure) is accompanied by framework structural changes similar to those previously reported for some carboxylate‐based hybrids. This breathing mechanism is accompanied by a volume increase of 55 %, while maintaining the topology and crystallinity of the material.
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.
