It also works with metals! Solid-phase synthesis procedures have been used to selectively construct linear, oligonuclear transition-metal complexes with precise length, sequence and direction (see scheme). Two synthetic strategies are described: formation of coordinative bonds or formation of covalent bonds in the chain elongation step.

Innocent or guilty? Catecholato–platinum(II) complexes with phenol-substituted α-diimine ligands are oxidised to the corresponding paramagnetic radical cationic complexes, as well as deprotonated to the corresponding base (see scheme). The radical cations are ortho-benzosemiquinoid in character (EPR spectroscopy). The diamagnetic anions can be described by para-iminoquinonoid resonance formulae and are luminescent at room temperature in fluid solution (static and time-resolved emission).

Fishing for ligands: The power of dynamic combinatorial chemistry in drug discovery is boosted by a design principle allowing multiple scaffold substituents. Library analysis is furthermore assisted by taking advantage of the UV/Vis spectra of the scaffolds, and an active compound is extracted from the mixture with high selectivity over less active compounds (see figure).

Primary function: The ruthenium-catalyzed hydrogenation of nitriles to give primary amines has been examined in detail with 18 different aromatic and aliphatic nitriles. Superior performance was achieved by using an in situ catalyst, [Ru(cod)methylallyl₂] (cod=1,5-cyclooctadiene) and DPPF (see scheme).

Cascading reactions: A new synthetic approach for the construction of multisubstituted 2-acyl furans with high diversity through IBX-mediated (IBX=2-iodoxybenzoic acid) cascade oxidation/cyclization of cis-2-en-4-yn-1-ols in dimethyl sulfoxide has been developed (see scheme). A mechanistic proposal involving IBX-promoted 5-exo-dig cyclization of an enynone intermediate is presented.

New family member: The “ferrocene–salimine” system depicted is a chiral three-dimensional relative of the ubiquitous salicyldaldimine ligand family. A short synthesis of the S_p enantiomer and its use in bis(“ferrocene–saliminato”)ZrCl₂ chemistry is reported.

Cobalt with a difference: In contrast to nickel- and palladium-catalyzed reactions, the cobalt-catalyzed reaction gave indenamine derivatives instead of isoquinoline derivatives. The difference of the regiochemistry and product formation with respect to the nickel-catalyzed reaction was explained. The indenamines are readily converted to the corresponding indenimines in the presence of tetrabutylammonium fluoride and can then be hydrolyzed to indenones (see scheme).

Under control: The synthesis of a MFI-zeolite was effectively controlled and the zeolite length was minimized to 20 nm by adding alkyltriethoxysilane to the conventional hydrothermal synthesis. Owing to intracrystal mesopores and a large external surface area, the zeolite materials (see figure for examples) exhibited a remarkably enhanced catalytic activity for reactions involving large organic molecules, as compared to conventional MFI-zeolites.

Copper cubes: An oxygen-bridged heptacopper(II) structure, [Cu₇(μ₃-OH)₆(μ₃-X)₂(D-pends)₃], bearing D-penicillaminedisulfide (D-H₂pends) as an auxiliary ligand was synthesized (see figure). This structure has a novel corner-sharing double-cubane framework without an intramolecular inversion center (i), which exhibits different magnetic behavior to that found in related double-cubane heptacopper(II) clusters with i.

A useful marker: An epitope-imprinting strategy leads to a synthetic phosphotyrosine-selective imprinted polymer receptor. Urea-mediated imprinting of N,O-protected phosphotyrosine (see picture) leads to a synthetic receptor capable of selectively extracting phosphotyrosine peptides in the presence of phosphoserine, phosphothreonine, and non-phosphorylated peptides.

Antibacterial agent 00F: Heptosides are found in important bacterial glycolipids such as lipopolysaccharide (LPS), the biosynthesis of which is targeted for the development of novel antibacterial agents. This work describes the synthesis of a fluorinated analog of ADP-L-glycero-β-D-manno-heptopyranose, the donor substrate of the heptosyl transferase WaaC, which catalyzes the incorporation of this carbohydrate into LPS (see scheme).

Cubane copper: Syntheses, X-ray and neutron diffraction crystal structures, magnetic properties, high-field–high-frequency EPR (HF-EPR), spin density, and theoretical description of a tetranuclear Cu^II complex (see figure) with a cubane-like structure are presented.

Autoxidation mechanism: The mechanism of autoxidation of ethoxylated surfactants has been investigated by DFT methods. In addition to the standard radical-chain mechanism, intermediate hydroxyl radicals can undergo intramolecular fragmentation reactions, as exemplified here.

Metal-promoted C₁ cannibalism: Separation of Me₃Al(PMe₃) occurs slowly when [La(AlMe₄)₃] reacts with trimethylphosphine and prolonged reaction periods lead to multiple CH bond activation as evidenced by the isolation of two distinct cuboid La₄Al₈ clusters and an La₅Al₉ cluster (see figure) bearing methylene, methine, and carbide units.

Charming chains: Crystal structures of one-dimensional Ag^I coordination polymers involving py-CONH-(CH₂)_n-py (py=pyridine; n=0, 1) derivatives were determined by single-crystal X-ray analyses; they showed biomimetic β-sheet and helical structural motifs (see picture).

All under control: The arene—perfluoroarene (Ar_H–Ar_F) interaction is found to be efficient for the self-assembly of oligo(para-phenylenevinylene)s (OPVs) in solution with controlled longitudinal fiber growth that leads to gelation (see picture). The fluorescence quenching that commonly occurs during the self-assembly of OPVs could be prevented by exciplex formation with N,N-dimethylaniline, which occurs only in the gel state.

Three chlorinated derivatives of the isomers C₇₈(2), C₇₈(3), and C₇₈(4) were synthesized by highly selective chlorination in a TiCl₄/Br₂ mixture (see scheme). Detailed analysis of the crystal structures of the three fullerene derivatives, C₇₈(2)Cl₁₈, C₇₈(3)Cl₁₈, and C₇₈(4)Cl₁₈, has revealed the presence of unusual, short intermolecular halogen–halogen contacts, the nature of which is discussed.

Bridging the gap: It is proposed that, after an initial conformational rearrangement of glutathione (GSH), a water molecule, acting as a bridge, is able to transfer the proton from the GSH thiol group to the GSH glutamyl α-carboxylate group (see models).

Optimised anion carriers: A study of 16 steroid-based anion transporters shows that changing substituents can have dramatic effects on transport rates. The current champion (see diagram) is effective in vesicle membranes with a transporter/lipid ratio of 1:250 000 (<2 transporter molecules per vesicle in the system studied).

Controlling the lactols: DFT, ab initio and experimental techniques have been used to probe the stereocontrol in the alkylation and oxy-Michael reactions of substituted δ-lactols (see scheme).

Take your pick! An ensemble system consisting of an energy acceptor (2) and an energy donor (1) exhibited selective luminescence enhancement upon binding to thymidine 5′-triphosphate (TTP) over other nucleotides in HEPES buffer.

Conformational changes count: The reactivity of the β-amino-γ-sultone system, with spiranic or non-spiranic substituents on C-5, is described. Theoretical and experimental studies show that the interaction of a base on the C-4 position of the spiranic systems induces a conformational change that breaks the planarity of the sultone ring, increasing the reactivity of the C-3 and N-4 positions towards electrophiles (see scheme).

Glucose nanosensor: A complex made from CdTe quantum dots (QDs) and glucose oxidase (GOx) has been facilely assembled to achieve enhanced enzymatic activity and a wide active temperature range of GOx. The principle is based on the fluorescence quenching of CdTe QDs and a cyclic electron-transfer mechanism (see scheme).

Thin gold films have been deposited on the inside of glass capillaries through which silanes and terminal alkynes are flowed (see scheme). Under microwave irradiation, hydrosilylation occurs very rapidly leading to the synthesis of vinylsilanes in very high chemical conversions. The films are reuseable and no leaching of gold nanoparticles into the eluent stream was observed (lower level of detection: δ=50 ppm).

Chemical shift prediction: Contributions from atomic p(Se), d(Se), and f(Se) are evaluated for various selenium compounds. The contributions from p(Se) are >96 % for Se*H_n (*=null, +, or −: n ≤ 3) and SeH₄ (T_d). The Me and X substitutions increase the p(Se) contributions. Consequently, σ^p(Se) can be substantially analyzed based on p(Se), especially by 4p(Se), for most of Se compounds.

An efficient and highly stereoselective synthesis of optically active γ-butyrolactones through the iodolactonization of 4,5-allenoic acid was observed (see scheme). The reaction of axially optically active 4,5-allenoic acids with N-iodosuccinimide (NIS) afforded the corresponding products without loss of chirality, whereas the substrates with a center of chirality at the 3-position reacted with I₂ to give the optically active trans-4,5-disubstituted γ-butyrolactones.

Film star: The synthesis, characterization, electrochemical and amphiphilic properties, and the patterning of Langmuir films of a series of single-tail amphiphiles and their copper(II)-containing complexes is discussed (see figure).

Extending the electrophilicity scale: Benzylidenemalonates are considerably less electrophilic than benzylidene Meldrum's acids, and allow us to extend the series of reference electrophiles (see graphic) used for the construction of nucleophilicity scales by six orders of magnitude on the low-reactivity end.

Too acidic anion receptor! 1:2 Fe^II and Ni^II complexes of thiosemicarbazones expose their thiourea subunits to the outside (see figure). They are prone to donate bifurcate H-bonds to anions. However, the metal centre exerts such a strong polarizing effect that most anions (e.g., CH₃COO⁻, NO₂⁻, F⁻) induce deprotonation of one N-H fragment of each thiosemicarbazone ligand.

The mechanism of the ene reaction of triazolinedione (RTAD) with simple alkenes depends on solvent polarity (see scheme). In aprotic solvents, a tight aziridinium imide intermediate with insignificant equilibration to its open intermediate is suggested. In protic solvents, large, non-stereochemically-dependent kinetic isotope effects suggest a loose aziridinium imide intermediate that equilibrates extensively with its open intermediate and the starting reagents.

Aromatic synthesis: Ring-closing olefin metathesis (RCM) of 4-methylene-1,7-octadien-3-ones 1, followed by isomerization of the carboncarbon double bond of 6-methylene-2-cyclohexenones 2 from exo to endo, produced various phenols 3. As an application of the method, the RCM/Mizoroki–Heck reaction of 1 was proven to be also effective for the synthesis of phenols having an additional substituent at ortho-benzylic position.

Art of attack: Aromatic ligand hydroxylation that occurs on reaction of a dicopper bis(imine) complex with O₂ was studied spectroscopically and kinetically, and the energetics of the hydroxylation pathway were determined theoretically. Calculations show that not the orbital of the μ-η²:η²-peroxo intermediate is involved in electrophilic attack on the arene ring of the ligand, which is the major barrier on the reaction pathway, but the σ* orbital, as depicted schematically.

Spare the rod! A mechanism for the nucleation and growth of nanocrystals (see graphic) was put forward, in view of the surface chemical thermodynamics, to explain the experimental results, which showed that the specific surface area increased as the initial concentrations were multiplied.

Things that glow red in water: The uniquely red-shifted and enhanced phosphorescence from the dicationic terpyridyl–Pt^II complexes with foldable ortho-PE(n) bridges (PE=phenyleneethynylene) in aerated H₂O/CH₃CN solvent mixtures was tentatively attributed to the molecular aggregation and intramolecular hydrophobic folding of the ortho-PE(n) (n≥3) moieties (see figure).

Fine tuning aluminum: A good synthetic route has been found for a series of dialuminum compounds (see figure) containing dianionic substituted pyrrolyl ligands. These compounds were used successfully as catalysts for the ring-opening polymerization of ε-caprolactone.

On again, off again: A new catechol-based derivative with complementary “off–on–off” and “on–off–on” emission profiles upon pH variation has been shown to exhibit excellent acidity detection over a broad pH range by applying a dual-wavelength detection methodology (see picture).

Au@Pt nanostructures for SPR-based sensing: Pt nanodots were formed on Au nanorods (see graphic) using a simple seed-mediated growth method. The Au@Pt nanostructure exhibited an evident longitudinal surface plasmon resonance (SPR) in the near-infrared region, thus opening the potential of using these nanostructures for SPR-based sensing.

A formal event in chemistry! “Formal” Ru^II-catalyzed [2+2+2] cycloaddition reactions of 1,6-diynes and alkenes were found to give bicyclic 1,3-cyclohexadienes (see scheme). The regio- and stereochemical course of the reaction depends on the substitution of the 1,6-diyne.

Sensitive detector: A novel carbon-nanotube (CNT)–alginate composite modified electrode was developed as a sensitive amperometric detector for capillary electrophoresis. The performance of this system was demonstrated by the separation and detection of five caffeic acid derivatives. The surface morphology of the CNT–alginate composites on an electrode is shown in the SEM image.

Pick'n'mix ZnSe nanostructures: Various wurtzite ZnSe architectural structures (see figure) have been successfully prepared through a novel tetraethylenepentamine-directed method in a ternary solution by adjusting the reaction parameters. This is the first preparation of complex hollow structures of ZnSe crystals with hierarchy through a simple solution-based route.