Gold and pearls : Multifunctional nanoparticles, each composed of a single, amine‐modified gold nanorod, decorated with multiple “pearls” of Fe3O4 nanoparticles capped with carboxy groups, are prepared. Their effectiveness in simultaneous targeting, dual‐mode imaging, and photothermal ablation of breast cancer cells is demonstrated.
Crystal‐clear structures : The first crystal structures of organometallic pincer–cutinase hybrids (see figure) provide insight into the 3D structural arrangement of both the protein and the organometallic pincer moiety, and reveal different binding modes for different pincers.
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).
Osmabenzenes can be easily synthesized from two η2‐coordinated olefin osmacycles in the presence of benzonitrile by means of facile hydrogen‐transfer conversions (see graphic). Mechanisms for the formation of osmabenzenes are proposed based on DFT calculations.
As easy as 1, 2, 3 : A palladium‐catalyzed three‐component coupling generates α,β‐unsaturated γ‐amino acids in a single step (see scheme). The reaction is believed to involve migration of a vinyl substituent to a highly electrophilic palladium carbene. Unlike previous synthetic approaches, this synthesis provides access to γ‐amino acids with non‐natural side chains.
Pepped up polymers : The synthesis and properties of novel chiral cyclic peptides designed to complex with suitable polymers through hydrogen bonding are described. A substituted cyclic peptide self‐assembles into supramolecular nanotubes and develops noncovalent interactions with poly(vinyl alcohol) (PVA) by means of its carboxyl side chains.
Propelling magnetism : Supramolecular organization leads to a remarkable dodecanuclear {Cu3Dy3}2 cluster with a “double–propeller” shape (see picture). The linkages of the CuDy units, both intramolecular and supramolecular, appear to be responsible for a drastic change in the single molecule magnetic behavior.
Searching for “intelligence” : Azurin–PNIPAM conjugates were prepared by site‐directed mutagenesis followed by protein reconstitution by using imidazole‐conjugated poly(N‐isopropylacrylamides). The polymer‐bound imidazole acts as a ligand in the active site of the blue copper protein azurin. The bioconjugates showed thermosensitive behavior in electron‐transfer processes with reduced cytochrome c.
Hot‐wired electrodes : Thin metallic wires (d=25 μm) are covered with a 3 μm layer of single‐walled carbon nanotubes (SWCNTs; see image) by electrophoresis from a suspension containing excess ionic surfactant. A pure SWCNT surface is achieved by heating the electrode in air. Strong differences between covered and bare metallic electrodes occur with in situ heating during electrochemical experiments.
An energy‐transfer cascade is generated from a cationic conjugated polymer (PFP) and negatively charged, Y‐shaped DNA labeled with three dyes at its termini (fluorescein (Fl), Tex Red, and Cy5). Multistep fluorescence resonance energy transfer regulates the fluorescence intensities of PFP and the dyes. Different types of logic gates can be operated by observing the emission wavelengths of different dyes with multiplex nucleases as inputs.
Down to the wire : Photobleaching dynamics show the exciton delocalization length of directly linked porphyrin arrays (see picture) to be about four or five porphyrin units at the single‐molecule level. This result provides a better understanding of how light‐signal transmission occurs in the solid state and gives a perspective for the porphyrin arrays to be used as single‐molecule photonic wires.
Slip between the sheets! The intercalation properties of lamellar solid acids have a profound impact on nitrogen doping as well as on the resultant visible‐light photocatalysis, and the effects depend strongly on the protonic acidities of the samples (see figure).
Tungsten tryst : A 4‐H‐butatrienylidene complex of tungsten was successfully isolated and structurally characterized. It undergoes a unique self‐coupling, which leads to a dimer (see picture; P pink, O red) with a cross‐conjugated π system and with electrochemically and magnetically active metal centers.
The aggregation and self‐assembly of square‐planar alkynylplatinum(II) complexes is induced by the use of a chiral polyacetylene with a helical conformation (see scheme). The chain helicity of the chiral polyacetylene under basic conditions has also been demonstrated to be enhanced by the presence of the positively charged platinum(II) complexes.
Better the second time around : The title compounds were synthesized by using a one‐pot double methylene transfer catalyzed by a heterobimetallic La/Li complex. Chiral amplification in the second step was the key to obtaining oxetanes in high enantiomeric excess (see scheme).
