A soft embrace for U : Replacement of C5Me5 by the soft PNP pincer ligand is a successful strategy to promote new reactivities and support new structures for the actinide series (see picture, py–O=pyridine‐N‐oxide). The specific electronic and steric properties of the PNP ligand enable access to previously unreported structures not available for the C5Me5 ligand set and support not only low‐valent uranium but also the high‐valent uranium(VI) ion.
Finely tuned: Carbon nanotubes are exposed to a CF4 radio‐frequency plasma (see picture). High‐resolution photoelectron spectroscopy shows that the treatment effectively grafts fluorine atoms onto the MWCNTs, altering the valence electronic states. Fluorine surface concentration can be tuned by varying the exposure time.
The right mix does the trick : Elusive {Ni0(η6‐arene)} moieties can be dramatically stabilized by the N‐heterocyclic silylene ligand 1 , which has a zwitterionic mesomeric structure. The σ, π‐acid–base synergism between nickel and 1 explains the unexpectedly high stability of the new silylene complexes 2 , which enables arene exchange studies at a Ni0 center. Addition of B(C6F5)3 to 2 affords the zwitterionic silylene complex 3 (see scheme, R=2,6‐iPr2C6H3).
Getting their feet wet : Low‐cost hydrocarbon surfactants act as fluid modifiers for supercritical carbon dioxide (scCO2). Increased terminal branching of the surfactant chains aids micelle formation (see middle picture: CO2 green), and more chains allows water to be incorporated (right, blue).
Aryl–alkyl cross‐coupling products are obtained by the iron‐catalyzed oxidative heterocoupling of organozinc reagents under mild conditions. This novel reaction pathway is versatile, allowing for the use of primary and secondary aliphatic diorganozinc reagents as coupling partners as well as tolerating functionalized aryl‐ and alkylzinc reagents.
Beyond stripes : The extreme lipophobicity of perfluorinated chains attached to amphiphilic thiolates triggers the formation of “stars” (or patches) surrounded by amphiphilic alkylthiolates in three‐dimensional self‐assembled monolayers. This strategy led to the first example of a water‐soluble multicompartment monolayer wrapped around a gold core.
Platinum recovery : Tripodal receptors incorporating urea, amido or sulfonamido hydrogen‐bond donors show high loading and selectivity for extraction of [PtCl6]2? over chloride (present in 60‐fold excess) from a low pH aqueous phase to organic media (see figure). The formation of neutral 2:1 [LH]+/[PtCl6]2? packages in organic solvents is supported by single‐crystal X‐ray structure determinations.
Predictions (DFT/B3LYP calculations) are that cyclopentadienyl lithium edge‐fused to [n]circulenes in a circum‐like manner should self‐assemble as rod‐like, nanometer long, supersandwich compounds (see figure). On the contrary, triazolyl lithium analogues prefer to dimerize thereby giving rise to shell‐like dimers of variable curvatures.
InBr 3 promotes the addition of ketene silyl acetals to monosubstituted alkynes to afford 2,2‐disubstituted alkenylindium compounds in high regio‐ and stereoselectivity (see scheme). In addition, the alkenylindium derivatives have been subsequently coupled with iodobenzene in the presence of a palladium catalyst.
Caught in the middle : The ionomycin calcium complex (see structure; O red, Ca green) was the target of an approach featuring the efficient asymmetric synthesis of an allene by a copper(I)‐mediated anti‐selective SN2′ reaction, a highly stereoselective gold(III)‐catalyzed cycloisomerization of an α‐hydroxyallene, and a Rh‐catalyzed rearrangement of an α‐diazo‐β‐hydroxyketone.
Please recycle! An amphiphilic polystyrene‐poly(ethylene glycol) resin‐dispersion of nanoparticles of platinum (ARP‐Pt) is developed, with the nanoparticles exhibiting a narrow size distribution throughout the resin. ARP‐Pt offers a sustainable chemistry alternative as a useful and readily recyclable catalyst for the aerobic oxidation of a wide variety of alcohols.
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.
An efficient catalytic asymmetric Friedel–Crafts alkylation of indoles with alkylidene malonates has been developed by using a chiral N,N′‐dioxide–Sc(OTf)3 complex as the catalyst (see scheme). Some optically active intermediates containing the indole skeleton have been synthesized, such as indolepropionic acid, tryptamines, and β‐carbolines. The coordination between the scandium atom and the chiral N,N′‐dioxide compound has been revealed by X‐ray structure analysis.
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.
Leading light : A series of zinc(II) bis‐terpyridine complexes (see picture) is investigated by means of DFT calculations combined with Bader's quantum theory of atoms in molecules. Raman spectroscopy experiments and studies of the electro‐optical properties of the complexes in solution and the solid state are also performed to examine their potential as new emissive materials in light‐emitting devices.
Opening gambit : A high‐level theoretical study on the relative stabilities of oxaphosphirane isomers and their Cr(CO)5 complexes is reported (see picture). Furthermore, thermodynamics and kinetics of possible ring‐opening reactions of these complexes in the presence of a {Cp2TiIIICl} fragment are theoretically investigated. The C? O bond cleavage is predicted to be the most efficient pathway, thus leading to reactive intermediates that are attractive for synthetic applications.
Round and round : Covalently bound spokes induce an efficient template‐directed cyclization towards a rigid molecular wheel (see figure) and afford dramatically increased shape‐persistence properties compared with non‐strutted macrocycles.
Ionic polymers in action : Conjugated polyelectrolytes are an emerging class of multifunctional polymers that feature π‐conjugated backbones festooned with ionic solubilizing groups. These materials have been exploited in a number of applications, including fluorescent biosensors, polymer light‐emitting diodes, and polymer solar cells. MV2+=methylviologen
In a row: Chemical concepts from the spin‐polarized conceptual DFT field are used to explain the spectrochemical and nephelauxetic series within a group of ruthenium complexes.
