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 .
The many faces of crystals : Silica mesoporous crystals were synthesized by using a co‐structure directing method. Structural defects in the crystals with Fdm symmetry—described as tetrahedrally close‐packed and consisting of 512 and 51264 polyhedra—were found (see figure). These defects were explained through the use of simulated TEM images. The defect formation is also discussed.
Although free from structural disorder , the new intermetallic compound Cd13?xInySb10 (see figure) displays similarly low thermal conductivity values as disordered thermoelectric β‐Zn4Sb3 with an isostructural framework.
A pigment of your imagination : A range of polycrystalline solid solutions of a zinc‐rich Znx?1MnxO system (see figure) have been prepared and studied in terms of their colour, diffuse reflectance spectra, Mn valence state and electronic structure. The intense optical absorption arises from Mn2+ doping and is thought to be due to forbidden or partially forbidden transitions between the valence and the conduction band.
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.
In tandem : Employing a molecular dyad and a cobalt‐based electrolyte gives a threefold‐increase in open‐circuit voltage (VOC) for a p‐type NiO device (VOC=0.35 V), and a fourfold better energy conversion efficiency. Incorporating these improvements in a TiO2/NiO tandem dye‐sensitized solar cell (TDSC), results in a TDSC with a VOC=0.91 V (see figure; CB=conductance band, VB= valence band).
Enriching peptides : Novel TiO2‐modified macroporous materials (Ti‐MOSF, see figure) have been synthesized with high surface area, large pore volume, and functional surfaces that are rich in coordinatively unsaturated TiIV species, which can be applied in the specific extraction of phosphopeptides and which show a preferential capture of multi‐phosphorylated peptides with low detection limits and high selectivity.
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.
New route to gas‐phase OH. : UV photolysis of gaseous o‐nitrobenzaldehyde forms OH radicals via the transformation into the ketene or o‐nitrosobenzoic acid intermediate (see figure). The OH. product is monitored by single‐photon laser‐induced fluorescence (LIF).
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.
Change the ligand, change the stereochemistry : 2,3‐Bis(acetoxy)‐1,3‐dienes are obtained in a stereocontrolled manner by a novel tandem 1,2‐/1,2‐bis(acetoxy) rearrangement (see scheme, R1 and R2 are δ+ stabilizing). Upon stabilization of the reaction intermediates, the ligand attached to gold controls the stereochemistry of the alkene in the second acetate migration, that is, N‐heterocyclic carbenes (NHC) favor cis alkenes, whereas phosphine ligands selectively afford trans olefins.
A cunning plan : In the multifunctional fluorescent probe MitoPY1 the phosphonium head group (red) targets mitochondria and the boronate group (green) responds to hydrogen peroxide. MitoPY1 reacts selectively with mitochondrial H2O2 in living cells, and an increase in fluorescence is triggered by the conversion of MitoPY1 into MitoPY1ox (yellow).
