Functionalized nanodiamonds : Various functional groups have been incorporated into the structures of the naturally occurring diamondoids [1(2)3]tetramantane and [12312]hexamantane (cyclohexamantane), which represent hydrogen‐terminated prism‐shaped nanodiamonds (see picture). The attachment points define the use of these diamond‐like molecules as geometric building blocks for a variety of applications.
Surrounded by six : A series of novel neutral hexacoordinate silicon(IV ) complexes with SiO2N4 skeletons, containing two bidentate monoanionic O,N ligands and two monoanionic NCX (X = O, S) ligands, was synthesized. The formation of the title compounds involved some unexpected transformations of the bidentate O,N ligands.
Metallophilic Au???Ag interactions exist in concentrated solutions as well as in the 2D polymeric solid‐state structure of [AuAg3(C6F5)(CF3CO2)3(CH2PPh3)]n (see picture for the asymmetric unit) according to EXAFS and pulsed‐gradient spin‐echo NMR spectroscopy measurements. Calculations support both the emission assignments and the existence of the metallophilic interactions in solution.
P makes it possible : The convenient oxidative synthesis of the 16‐electron organophosphorus iron sandwich complex [Fe(η4‐P2C2tBu2)2] (see structure) suggests that the elusive all‐carbon complex [Fe(η4‐C4H4)2] is a viable synthetic target.
From imines to amines through catalysis by IrI complexes of a new type of P,N ligand (see scheme): This reaction affords the corresponding optically active amines with up to 98 % ee and has also been used with perfect stereoselectivity in the asymmetric synthesis of sertraline ( 1 ), an important antidepressant chiral drug.
Towards polythiophene polyrotaxanes : The β‐substituted terthiophene [2]rotaxanes have been synthesized (see figure). Basic optical and electrochemical properties of the synthesized [2]rotaxanes are also reported.
Chlorocarbon solvents (solv=CH2Cl2, CHCl3) are suggested to play an active role in the oxidative addition of halogens, X2 (X=Cl, Br, I), to homoleptic d8 perfluoromethyl and ‐phenyl platinum(II ) species [Pt(RF)4]2? (RF=CF3, C6F5). The perfluoromethyl group, CF3, has been found to be considerably less prone to undergo reductive elimination processes, and is, therefore, more suitable for stabilizing organoplatinum(IV ) derivatives (see scheme).
Pincers do something for U that sandwiches don′t : The dead‐ends in the metallocene chemistry of the actinides can be circumvented by using a soft PNP pincer ligand (see scheme). The PNP ligand has been shown to be flexible, hemilabile, and capable of stabilizing low‐ and high‐valent uranium species. The bis(PNP) framework is a valuable alternative to the (C5Me5)2 ligand set, offering distinct structures and reaction patterns.
Pushing the limits of coordination chemistry : The most weakly coordinated silver complexes of the very weakly coordinating solvents dichloromethane and liquid sulfur dioxide were prepared. Special techniques at low temperatures and the use of weakly coordinating anions allowed structural characterization of [Ag(OSO)][Al{OC(CF3)3}4], [Ag(OSO)2/2][SbF6], and [Ag(Cl2CH2)2][SbF6] (see figure). An investigation of the bonding shows that these complexes are mainly stabilized by electrostatic monopole–dipole interactions.
The true ground state of 1 is a matter of debate, but for clarity and convenience the allene resonance form 1 a , is the most appropriate. The arguments for aromaticity made by Christl and Engels are shown to be incorrect.
Enzyme in action : The accumulated single‐molecule image (see picture) of phospholipase A2 (PLA2) 15–21 min after its injection on a lipid membrane shows transient interactions of PLA2 (blue) with the membrane surface and stable binding to the boundaries of membrane structure defects. The adsorbed PLA2 molecules move with a speed below the experimental resolution of 40 nm min?1.
A rare phosphorus analogue of the elusive complex bis(η4‐cyclobutadiene)iron(0) is reported by K. Lammertsma et al. in their Communication on page 3104 ff. The background of the cover picture shows John Montagu (1718–1792), 4th Earl of Sandwich and 1st Lord of the Admiralty, who certainly would not have dreamt that an important class of organometallic compounds, sandwich complexes, would bear his name one day. The synthesis of [Fe(P2C2tBu2)2] shows that sandwich complexes are still topical objects of research.
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).
Dramatic rate enhancement of reductive elimination of [Ar‐Pd‐C] was observed in the presence of a phosphine/electron‐deficient olefin ligand. Through systematic kinetic investigations of the Negishi coupling of ethyl 2‐iodobenzoate with alkylzinc chlorides (see scheme), the rate constants for reductive elimination of [Ar‐Pd‐C] were determined to be greater than 0.3 s?1, which is about four or five orders of magnitude greater than values reported previously.
Breaking barriers : In agreement with experimental evidence, it was found by means of high‐level DFT calculations that the Cr(CO)3 metal fragment considerably reduces the reaction energy barrier—for both the concerted and stepwise reaction mechanisms (see graphic)—of the Diels–Alder reaction of butadiene on (5,5) carbon nanotubes.
Designing superacids: A computational study of protonated boratabenzenes and the gas‐phase acidity of their conjugate acids is presented. Conjugate acids of boratabenzenes substituted with CN or CF3 groups (see figure) are highly acidic species; the protonated hexacyanoboratabenzene and hexakis(trifluoromethyl)boratabenzene have computational gas‐phase acidities of 250.5 and 276.8 kcal mol?1, respectively.
Metal‐stabilized belts : A torus, 3 , consisting of three four‐ and three eight‐membered conjugated rings and stabilized by (RCp)Co‐ and (RCp)Rh‐ units, was generated by irradiation of [(RCp)Co(CO)2] and [(RCp)Rh(C2H4)2], respectively, and 1 .
Aerobic oxidation : Mechanisms of aerobic oxidation of the PdII(OAc)2/pyridine catalyst system were evaluated by using density functional theory methods. The results reveal that labile monodentate ligands, such as pyridine, favor a catalyst reoxidation pathway that proceeds via Pd0, rather than direct reaction of O2 with a PdII–hydride intermediate (see scheme).
Cobalt cyclopentadienyl complexes incorporating a fumarate and a CO ligand (see picture) efficiently catalyze inter‐ and intramolecular [2+2+2] cycloadditions of alkynes, nitriles, and/or alkenes to give benzenes, pyridines, or 1,3‐cyclohexadienes. Unlike catalysts such as [CpCo(CO)2] or [CpCo(C2H4)2] (Cp=C5H5), they are air‐stable, easy to handle, compatible with microwave conditions, and do not necessarily require irradiation to be active.
