Chemistry - A European Journal

Cover image for Vol. 19 Issue 50

December 9, 2013

Volume 19, Issue 50

Pages 16841–17215

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    8. Correspondence
    1. You have free access to this content
      Cover Picture: Highly Asymmetrical Porphyrins with Enhanced Push–Pull Character for Dye-Sensitized Solar Cells (Chem. Eur. J. 50/2013) (page 16841)

      Prof. Dr. Kei Kurotobi, Yuuki Toude, Kyosuke Kawamoto, Yamato Fujimori, Prof. Dr. Seigo Ito, Dr. Pavel Chabera, Prof. Dr. Villy Sundström and Prof. Dr. Hiroshi Imahori

      Article first published online: 5 DEC 2013 | DOI: 10.1002/chem.201390198

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      A porphyrin π system has been modulated by enhancing the push–pull character with highly asymmetric substitution for use in dye-sensitized solar cells. Electron injection from the porphyrin excited singlet states to a conduction band of the TiO2 electrode is very fast, whereas charge recombination is very slow, conditions ideal for high device performance. For more details see the Full Paper by V. Sundström, H. Imahori et al. on page 17075 ff.

    2. You have free access to this content
      Back Cover: Synthesis, Structure, and Reactivity of Lewis Base Stabilized Plumbacyclopentadienylidenes (Chem. Eur. J. 50/2013) (page 17220)

      Prof. Dr. Masaichi Saito, Tomoki Akiba, Misumi Kaneko, Toshiaki Kawamura, Dr. Minori Abe, Prof. Dr. Masahiko Hada and Prof. Dr. Mao Minoura

      Article first published online: 5 DEC 2013 | DOI: 10.1002/chem.201390201

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      Plumbacyclopentadienylidenes  in which the lead atom is coordinated to a variety of Lewis bases, including THF, exhibit interesting behavior and reactivity. In their Full Paper on page 16946 ff., M. Saito et al. show that the THF adduct, which is a rare example of a 10-X-4 species, reacts with trifluoroborane or trichlorogallane to afford fluoroborole and chlorogallole, respectively.

  2. Graphical Abstract

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    8. Correspondence
  3. News

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    8. Correspondence
  4. Review

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    8. Correspondence
    1. Host–Guest Systems

      Pillararene-Based Assemblies: Design Principle, Preparation and Applications (pages 16862–16879)

      Dr. Huacheng Zhang and Prof. Dr. Yanli Zhao

      Article first published online: 18 NOV 2013 | DOI: 10.1002/chem.201301635

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      Supramolecular architectures: Recent advancements on pillararene-based assemblies by discussing the driving forces of the assembly formations, for example, host–guest interactions and solvent effects, as well as classifying various pillararene-based assembly architectures, for example, pillararene-based interlocked structures and topological supramolecular assemblies are described.

  5. Communications

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    8. Correspondence
    1. Organic Synthesis

      Copper-Catalyzed Aromatic C[BOND]H Bond Cyanation by C[BOND]CN Bond Cleavage of Inert Acetonitrile (pages 16880–16886)

      Xuezhen Kou, Mengdi Zhao, Xixue Qiao, Yamin Zhu, Xiaofeng Tong and Prof. Dr. Zengming Shen

      Article first published online: 21 NOV 2013 | DOI: 10.1002/chem.201303637

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      Cut and paste! A Cu-catalyzed aromatic C[BOND]H cyanation with acetonitrile as the nitrile source by C[BOND]CN cleavage has been developed (see scheme; TMEDA=N,N,N′,N′-tetramethylethylenediamine). The reaction is catalytic in copper, and it is found that using (Me3Si)2 as an additive plays a critical role in promoting C[BOND]CN cleavage and enhancing the reaction rate.

    2. DNA Nanostructures

      Regulation of B–Z Conformational Transition and Complex Formation with a Z-Form Binding Protein by Introduction of Constraint to Double-Stranded DNA by using a DNA Nanoscaffold (pages 16887–16890)

      Prof. Dr. Masayuki Endo, Masahiro Inoue, Dr. Yuki Suzuki, Chigusa Masui, Dr. Hironobu Morinaga, Kumi Hidaka and Prof. Dr. Hiroshi Sugiyama

      Article first published online: 5 NOV 2013 | DOI: 10.1002/chem.201303830

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      B–Z transition: A constrained and rotatable double-stranded DNA, in which the rotational freedom was controlled by its placement into a DNA nanoscaffold, was designed (see scheme). The Z α β protein bound preferentially to the rotatable strand rather than the constrained strand, even using the same CG sequence.

    3. Supramolecular Polymers

      X-ray Structure of a Porphyrin–Tetramethylcucurbit[6]uril Supramolecular Polymer (pages 16891–16896)

      Prof. Xin Xiao, Junshan Sun and Prof. Dr. Jianzhuang Jiang

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201303530

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      A host–guest supramolecular polymer was constructed from cucurbit[6]uril host molecules (orange) and porphyrin guest molecules (red and blue) and its formation depends on host-enhanced hydrogen-bonding interactions in combination with ion-dipole interactions. The polymer is the first structurally characterized cucurbit[n]uril–porphyrin supramolecular polymer.

    4. Energy Conversion

      Ordered Mesoporous Core/Shell SnO2/C Nanocomposite as High-Capacity Anode Material for Lithium-Ion Batteries (pages 16897–16901)

      Dr. Hao Liu, Dr. Sheng Chen, Prof. Dr. Guoxiu Wang and Prof. Dr. Shi Zhang Qiao

      Article first published online: 4 NOV 2013 | DOI: 10.1002/chem.201303400

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      High on energy: An ordered mesoporous core/shell structured SnO2/C nanocomposite was obtained from a facile vacuum-assisted impregnation route by using SBA-15 as a hard template. The nanocomposoite exhibits high specific capacity and excellent high-rate performance as an anode material for lithium-ion battery (see graph).

    5. Single-Molecule Magnets

      On-Surface Magnetometry: The Evaluation of Superexchange Coupling Constants in Surface-Wired Single-Molecule Magnets (pages 16902–16905)

      Dr. Erik Tancini, Dr. Matteo Mannini, Dr. Philippe Sainctavit, Dr. Edwige Otero, Prof. Dr. Roberta Sessoli and Prof. Dr. Andrea Cornia

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201303585

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      A comfortable environment: Interaction with a gold surface fully preserves the spin structure of a Fe3Cr single-molecule magnet of current interest in molecular spintronics. Magnetic polarization at metal sites is measured over a broad temperature range (from 10 to 300 K) by X-ray magnetic circular dichroism (XMCD), which provides the required monolayer sensitivity. The data are used to evaluate Fe[BOND]Cr superexchange coupling interactions, which compare well with bulk-phase values in both sign and strength (see figure).

    6. Hydroformylation

      Ligand–Metal Cooperating PC(sp3)P Pincer Complexes as Catalysts in Olefin Hydroformylation (pages 16906–16909)

      Sanaa Musa, Oleg A. Filippov, Prof. Natalia V. Belkova, Prof. Elena S. Shubina, Gleb A. Silantyev, Prof. Dr. Lutz Ackermann and Prof. Dmitri Gelman

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201303311

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      Ligand–metal cooperation: A new ligand–metal cooperating catalyst for the hydroformylation of olefins is described (see scheme). The mechanism of the H2 activation and C[BOND]H bond formation of the catalyst involves an intramolecular cooperation between the structurally remote functionality and the metal center and proceeds without change of the oxidation state of the metal.

    7. Trifluoromethylation

      Copper-Catalyzed Trifluoromethylation and Cyclization of Aromatic-Sulfonyl-Group-Tethered Alkenes for the Construction of 1,2-Benzothiazinane Dioxide Type Compounds (pages 16910–16915)

      Xiang Dong, Rui Sang, Qiang Wang, Dr. Xiang-Ying Tang and Prof. Min Shi

      Article first published online: 5 NOV 2013 | DOI: 10.1002/chem.201303623

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      A multi-talented system: An efficient copper-catalyzed tandem trifluoromethylation/annulation of an electron-deficient aromatic ring has been developed. This method provides a powerful and straightforward way to synthesize trifluoromethylated 1,2-benzothiazinane dioxides under mild conditions (see scheme). The mechanism was investigated by a series of kinetic experiments and isotopic labeling studies.

    8. Prebiotic Chemistry

      Meteorites as Catalysts for Prebiotic Chemistry (pages 16916–16922)

      Prof. Raffaele Saladino, Dr. Giorgia Botta, Dr. Michela Delfino and Prof. Ernesto Di Mauro

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201303690

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      From outer space: Twelve meteorite specimens, representative of their major classes, catalyse the synthesis of nucleobases, carboxylic acids, aminoacids and low-molecular-weight compounds from formamide (see figure). Different chemical pathways are identified, the yields are high for a prebiotic process and the products come in rich and composite panels.

    9. Inhibitors

      Optimizing Divalent Inhibitors of Pseudomonas aeruginosa Lectin LecA by Using A Rigid Spacer (pages 16923–16927)

      Francesca Pertici, Dr. Nico J. de Mol, Dr. Johan Kemmink and Prof. Dr. Roland J. Pieters

      Article first published online: 4 NOV 2013 | DOI: 10.1002/chem.201303463

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      Rigid spacers: Optimal highly potent divalent ligands of the P. aeruginosa lectin LecA have been prepared. The ligands consist of a rigid spacer derived from glucose–triazole units (see figure). Systematic variation of the number of spacer units and the aglycon linker led to a 7500-fold enhancement in potency.

    10. Visible-Light Photocatalysis

      Visible-Light-Induced Radical Cyclization of Trifluoroacetimidoyl Chlorides with Alkynes: Catalytic Synthesis of 2-Trifluoromethyl Quinolines (pages 16928–16933)

      Xichang Dong, Youwei Xu, Jing Jing Liu, Yumin Hu, Tiebo Xiao and Prof. Dr. Lei Zhou

      Article first published online: 5 NOV 2013 | DOI: 10.1002/chem.201303149

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      A simple and efficient method for the synthesis of 2-trifluoromethyl quinolines by means of visible-light-induced radical cyclization of trifluoroacetimidoyl chlorides with alkynes has been developed. This protocol allows the generation of imidoyl radicals by activation of C(sp2)[BOND]Cl bonds using a photoredox catalyst under mild and environmentally friendly conditions (see scheme).

    11. Peptide Activation

      Epimerization-Free C-Terminal Peptide Activation (pages 16934–16937)

      Stanimir Popovic, Hans Bieräugel, Dr. Remko J. Detz, Dr. Alexander M. Kluwer, Jelmer A. A. Koole, Dieuwertje E. Streefkerk, Prof. Dr. Henk Hiemstra and Dr. Jan H. van Maarseveen

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201303347

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      Smooth operation: C-terminal peptide activation with full stereointegrity was accomplished using a copper(II)-mediated coupling reaction of carboxylic acids with arylboroxines (see scheme, NCL = native chemical ligation, Boc = tert-butoxycarbonyl). This method allows epimerization-free activation and ligation of peptides with racemization-prone phenylglycine at the C terminus.

  6. Full Papers

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    8. Correspondence
    1. Catalyst Dynamics

      Carbon Dynamics on the Molybdenum Carbide Surface during Catalytic Propane Dehydrogenation (pages 16938–16945)

      Dr. Benjamin Frank, Dr. Thomas P. Cotter, Dr. Manfred E. Schuster, Prof. Dr. Robert Schlögl and Dr. Annette Trunschke

      Article first published online: 18 NOV 2013 | DOI: 10.1002/chem.201302420

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      Black is beautiful: The active surface of mesoporous bulk molybdenum carbide catalysts during catalytic propane dehydrogenation sensitively responds to reaction conditions (see scheme). The delicate balance between surface coking and irreversible bulk oxidation affects the product distribution. The reactivity can be controlled by vanadium doping, reaction temperature, or by adding H2, H2O, or CO2 to the feed.

    2. Metal Complexes

      Synthesis, Structure, and Reactivity of Lewis Base Stabilized Plumbacyclopentadienylidenes (pages 16946–16953)

      Prof. Dr. Masaichi Saito, Tomoki Akiba, Misumi Kaneko, Toshiaki Kawamura, Dr. Minori Abe, Prof. Dr. Masahiko Hada and Prof. Dr. Mao Minoura

      Article first published online: 15 NOV 2013 | DOI: 10.1002/chem.201303672

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      Plumbacyclopentadienylidenes, in which the lead atoms have divalent states and are coordinated by THF, pyridine, and an N-heterocyclic carbene, were synthesized and characterized. The THF-stabilized compound can be regarded as a rare example of hypervalent 10-X-4 species, which converts into a plumbylene dimer and reacts with trifluoroborane and trichlorogallane to afford the corresponding fluoroborole and chlorogallole, respectively (see scheme; R=Me2tBuSi).

    3. Solid-State Structures

      The Borosulfate Story Goes on—From Alkali and Oxonium Salts to Polyacids (pages 16954–16962)

      Dipl.-Chem. Michael Daub, Dr. Karolina Kazmierczak, Prof. Dr. Henning A. Höppe and Prof. Dr. Harald Hillebrecht

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201303012

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      The chains that bind: New borosulfates increase the number of representatives of this class to 11 with six different structural principles (see figure). The dimensionality depends on the connectivity pattern and the ratio of BO4 to SO4 tetrahedra.

    4. Conformation Analysis

      Mixed Oligoureas Based on Constrained Bicyclic and Acyclic β-Amino Acids Derivatives: On the Significance of the Subunit Configuration for Folding (pages 16963–16971)

      Dr. Christophe André, Dr. Baptiste Legrand, Laure Moulat, Emmanuel Wenger, Dr. Claude Didierjean, Dr. Emmanuel Aubert, Dr. Marie Christine Averlant-Petit, Prof. Jean Martinez, Dr. Muriel Amblard and Dr. Monique Calmes

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201302829

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      BAC into the fold: In mixed oligourea alternating (R)-bicyclic amino carbamoyl (BAC)γ and acyclic (S)-β3-homo-amino acid residues, the BAC residue was able to impose a sterically unfavorable Cα[BOND]Cβ synclinal conformation to the adjacent acyclic residues, promoting the helical folding of the oligourea (see figure).

    5. Chirality

      Chiral Photoresponsive Tetrathiazoles That Provide Snapshots of Folding States (pages 16972–16980)

      Dr. Takuya Nakashima, Kyohei Yamamoto, Yuka Kimura and Prof. Tsuyoshi Kawai

      Article first published online: 8 NOV 2013 | DOI: 10.1002/chem.201302564

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      Tether report: Tetra(2-phenylthiazole)s that tether chiral groups at both of the end units preferentially fold into one-handed helices to show a stereoselective photoinduced 6π-electrocyclization reaction (see figure).

    6. Cycloaddition

      Synthesis of Multifunctionalized 1,2,3,4-Tetrahydropyridines, 2,3-Dihydropyridin-4(1H)-ones, and Pyridines from Tandem Reactions Initiated by [5+1] Cycloaddition of N-Formylmethyl-Substituted Enamides to Isocyanides: Mechanistic Insight and Synthetic Application (pages 16981–16987)

      Chuan-Hu Lei, Dr. De-Xian Wang, Dr. Liang Zhao, Prof. Dr. Jieping Zhu and Prof. Dr. Mei-Xiang Wang

      Article first published online: 5 NOV 2013 | DOI: 10.1002/chem.201303221

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      One stone, three birds! Highly efficient tandem reactions initiated by an identical Zn(OTf)2-mediated [5+1] cycloaddition of N-formylmethyl-substituted tertiary enamides to isocyanides led to the formation of multifunctionalized 1,2,3,4-tetrahydropyridine, 2,3-dihydropyridin-4(1H)-one, and pyridine derivatives (see scheme).

    7. Anion–π Interactions

      Preorganized Anion Traps for Exploiting Anion–π Interactions: An Experimental and Computational Study (pages 16988–17000)

      Anne Bretschneider, Dr. Diego M. Andrada, Dr. Sebastian Dechert, Steffen Meyer, Prof. Dr. Ricardo A. Mata and Prof. Dr. Franc Meyer

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201302598

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      On the hunt for anions: Two neutral anion receptors have been designed that feature a central NH harpoon, directing the guest into a preorganized clamp of two electron-deficient appended arenes that are preorganized for anion–π interactions (see figure). The ability of the receptors to bind Cl and Br has been evaluated. Detailed computational analyses of the host–guest systems with local correlation methods allowed for quantification of individual contributions to the binding energy.

    8. Carbohydrate Chemistry

      A Unified Strategy for the Synthesis of Mucin Cores 1–4 Saccharides and the Assembled Multivalent Glycopeptides (pages 17001–17010)

      Dipl.-Chem. Christian Pett, M. Sc. Manuel Schorlemer and Dr. Ulrika Westerlind

      Article first published online: 4 NOV 2013 | DOI: 10.1002/chem.201302921

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      One for all! In a convergent approach starting from a shared early-stage intermediate by differentiation in the glycoside acceptor reactivity, a common disaccharide building block allows for the creation of extended glycosylated amino acids carrying the mucin type-2 cores 1–4 saccharides (see scheme). The amino acids are incorporated into peptides for multivalent glycan display. Ac=acetyl, Troc=trichloroethoxycarbonyl, TBS=tert-butyl dimethylsilyl

    9. Fused-Ring Systems

      Conformational Change from a Twisted Figure-Eight to an Open-Extended Structure in Doubly Fused 36π Core-Modified Octaphyrins Triggered by Protonation: Implication on Photodynamics and Aromaticity (pages 17011–17020)

      Ganesan Karthik, Dr. Jong Min Lim, Dr. A. Srinivasan, Dr. C. H. Suresh, Prof. Dr. Dongho Kim and Prof. Dr. Tavarekere K. Chandrashekar

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201302020

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      Figure-eight to open structure: A major structural change from a figure-eight conformation to an open-extended conformation upon addition of two protons to an expanded 36π fused octaphyrin cavity is reported (see figure). Such a change in conformation results in an increase in singlet lifetime, two-photon absorption cross-section values, and a change in aromaticity from a (4n)π nonaromatic to antiaromatic electronic structure.

    10. Clusters

      Synthesis, Characterization, and Thermal Behavior of Carboranyl–Styrene Decorated Octasilsesquioxanes: Influence of the Carborane Clusters on Photoluminescence (pages 17021–17030)

      Albert Ferrer-Ugalde, Emilio José Juárez-Pérez, Francesc Teixidor, Clara Viñas and Dr. Rosario Núñez

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201302493

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      Turn up the heat: A thorough study of the thermal stability and photoluminescence properties of polyhedral oligomeric silsesquioxanes (POSS cages) decorated with eight carboranyl–styrene fragments (see figure) is described. Attachment of the carboranyl–styrene fragments to the POSS core by cross-metathesis induces important changes in the thermal stability and the photoluminescence intensity of these compounds with respect to the free monomers.

    11. Anticancer Complexes

      Increasing the Bioavailability of RuIII Anticancer Complexes through Hydrophobic Albumin Interactions (pages 17031–17042)

      Dr. Michael I. Webb, Boris Wu, Thalia Jang, Ryan A. Chard, Dr. Edwin W. Y. Wong, May Q. Wong, Dr. Donald T. T. Yapp and Prof. Charles J. Walsby

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201302671

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      Albumin: friend or foe? A series of Ru-based anticancer candidates has been synthesized with pyridine-based ligands (see figure), to probe their non-coordinate interactions with albumin. Significant stabilization of hydrophobic binding was demonstrated and correlated with reduced coordination of the complexes with the protein. Biological testing suggests that this is a promising strategy for enhancing the solubility and anticancer activity of Ru complexes.

    12. Transcription Factors

      Spectroscopic Elucidation of the Inhibitory Mechanism of Cys2His2 Zinc Finger Transcription Factors by Cobalt(III) Schiff Base Complexes (pages 17043–17053)

      Marie C. Heffern, Dr. Josh W. Kurutz and Prof. Thomas J. Meade

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201301659

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      Uncrossing fingers: Transition-metal complexes are emerging as promising zinc finger transcription factor inhibitors (see scheme). The dynamic structure of zinc fingers can make inhibition difficult to characterize. An array of spectroscopic studies is described to elucidate the specific interaction between cobalt(III) complexes and zinc-finger peptides.

    13. Mutagenesis Studies

      Structure-Based Optimization of the Terminal Tripeptide in Glycopeptide Dendrimer Inhibitors of Pseudomonas aeruginosa Biofilms Targeting LecA (pages 17054–17063)

      Dr. Rameshwar U. Kadam, Myriam Bergmann, Dr. Divita Garg, Gabriele Gabrieli, Dr. Achim Stocker, Dr. Tamis Darbre and Prof. Dr. Jean-Louis Reymond

      Article first published online: 4 NOV 2013 | DOI: 10.1002/chem.201302587

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      Breaking down biofilms: X-ray crystal-structure analysis of protein–ligand complexes and docking were used as the basis to optimize the terminal tripeptide of GalAG2, a tetravalent glycopeptide dendrimer inhibitor of the galactose-specific lectin LecA and of Pseudomonas aeruginosa biofilms. The study led to the discovery of new glycopeptide dendrimers with improved LecA binding, biofilm inhibition, and biofilm-dispersal properties (see figure for a close-up view of the GalA-WRI galactotripeptide bound to LecA).

    14. Molecular Magnets

      Role of Dicarboxylate Linkers in MnIII-Salicylaldoximate Based Extended Structures: Synthesis, Structures, and Magnetic Behavior (pages 17064–17074)

      Sandip Mukherjee and Prof. Dr. Partha Sarathi Mukherjee

      Article first published online: 4 NOV 2013 | DOI: 10.1002/chem.201302377

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      Four new MnIII-salox extended complexes were synthesized and found to differ in their basic and overall structures depending upon the bridging dicarboxylates (see scheme). The Mn6 cluster-based complexes showed single molecular magnet (SMM) behavior, while the Mn3-based complex is dominantly antiferromagnetic, which was confirmed by DFT calculations.

    15. Solar Cells

      Highly Asymmetrical Porphyrins with Enhanced Push–Pull Character for Dye-Sensitized Solar Cells (pages 17075–17081)

      Prof. Dr. Kei Kurotobi, Yuuki Toude, Kyosuke Kawamoto, Yamato Fujimori, Prof. Dr. Seigo Ito, Dr. Pavel Chabera, Prof. Dr. Villy Sundström and Prof. Dr. Hiroshi Imahori

      Article first published online: 13 NOV 2013 | DOI: 10.1002/chem.201303460

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      Improving performance in organic solar cells: A porphyrin π system (ZnPBAT; see figure) has been modulated by enhancing the push–pull character with highly asymmetric substitution for use in dye-sensitized solar cells. The enhanced porphyrin-sensitized solar cell exhibited more than 10 % power conversion efficiency, which exceeded that of the benchmark porphyrin. The rational molecular design concept will open the possibilities of further improving cell performance in organic solar cells.

    16. Donor–Acceptor Systems

      Photoinduced Charge Separation in Zinc–Porphyrin/Tungsten–Alkylidyne Dyads: Generation of Reactive Porphyrin and Metallo Radical States (pages 17082–17091)

      Davis B. Moravec and Prof. Michael D. Hopkins

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201303118

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      Dual activation: Zinc–porphyrin/tungsten–alkylidyne dyads undergo intramolecular electron transfer upon porphyrin excitation (see scheme). This porphyrin reductive quenching yields the [ZnPor][W+] charge-separated state. The porphyrin and tungsten radicals are capable of sensitizing CO2 reduction catalysts and initiating H2 oxidation, respectively, making energy-storing photochemistry without conventional sacrificial donors possible.

    17. Host–Guest Systems

      Social Isomers of Picolines in a Small Space (pages 17092–17096)

      Prof. Dariush Ajami, Giannoula Theodorakopoulos, Ioannis D. Petsalakis and Prof. Julius Rebek Jr.

      Article first published online: 12 NOV 2013 | DOI: 10.1002/chem.201303117

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      Let's socialize! Encapsulation complexes permit the observation of molecules under conditions of limited motion. Inside capsules, molecular encounters are prolonged, prearranged, and protected from the medium, in contrast to the short-lived and random encounters that occur in bulk solution. Herein, the interaction of α-, β-, and γ-picolines in a cylindrical capsule is described (see figure).

      Corrected by:

      Corrigendum: Corrigendum: Social Isomers of Picolines in a Small Space

      Vol. 20, Issue 37, 11609, Article first published online: 29 AUG 2014

    18. Aromaticity

      Diazadioxa[8]circulenes: Planar Antiaromatic Cyclooctatetraenes (pages 17097–17102)

      Thomas Hensel, Denis Trpcevski, Christopher Lind, Rémi Grosjean, Dr. Peter Hammershøj, Dr. Christian B. Nielsen, Dr. Theis Brock-Nannestad, Bjarne E. Nielsen, Magnus Schau-Magnussen, Prof. Boris Minaev, Gleb V. Baryshnikov and Dr. Michael Pittelkow

      Article first published online: 5 NOV 2013 | DOI: 10.1002/chem.201303194

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      Plane to see: New [8]circulenes are planar when an adequate number of heteroatoms are in the outer ring. This leads to the antiaromatic nature of the central cyclooctatetraene ring. A new class of antiaromatic [8]circulenes, the diazadioxa[8]circulenes, have been prepared by means of a new acid-mediated oxidative dimerization of 3,6-dihydroxycarbazoles to yield the new [8]circulenes in high yields (see scheme; R=benzyl or propyl).

    19. Nanotubes

      An Iron Impurity in Multiwalled Carbon Nanotube Complexes with Chitosan that Biomimics the Heme-Peroxidase Function (pages 17103–17112)

      Prakasam Gayathri and Prof. Annamalai Senthil Kumar

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201303075

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      Impure advantage: For the first time, the heme-peroxidase-biomimicking property of an iron impurity in multi-walled carbon nanotubes (MWCNT) when combined with a chitosan biopolymer is reported. The iron species forms a complex with the amino function and shows a well-defined redox peak similar to the heme protein and selectively mediates hydrogen peroxide and dissolved oxygen in a physiological solution (see figure, CHIT = chitosan).

    20. Carbenes

      The Ambivalent Chemistry of a Free Anionic N-Heterocyclic Carbene Decorated with a Malonate Backbone: The Plus of a Negative Charge (pages 17113–17124)

      Dr. Vincent César, Stéphane Labat, Dr. Karinne Miqueu, Dr. Jean-Marc Sotiropoulos, Rémy Brousses, Dr. Noël Lugan and Dr. Guy Lavigne

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201303184

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      An adaptive carbene: The lithium salt of the free anionic “maloNHC” is prone to react with a variety of organic substrates, including both classical electrophilic organic reagents and nucleophilic ones, like tert-butylisocyanide. It is also seen to react with 4-chlorobenzaldehyde through a formal C[BOND]H activation and to activate N[BOND]H, Si[BOND]H, and B[BOND]H bonds (see scheme; Mes=mesityl). The clue to such an ambivalent behavior is a dynamic variation of orbital energy levels under the control of the counterion.

    21. Coordination Chemistry

      La2@Cs(17 490)-C76: A New Non-IPR Dimetallic Metallofullerene Featuring Unexpectedly Weak Metal–Pentalene Interactions (pages 17125–17130)

      Dr. Mitsuaki Suzuki, Dr. Naomi Mizorogi, Tao Yang, Prof. Dr. Filip Uhlik, Prof. Dr. Zdenek Slanina, Prof. Dr. Xiang Zhao, Prof. Dr. Michio Yamada, Prof. Dr. Yutaka Maeda, Prof. Dr. Tadashi Hasegawa, Prof. Dr. Shigeru Nagase, Prof. Dr. Xing Lu and Prof. Dr. Takeshi Akasaka

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201302821

      Thumbnail image of graphical abstract

      Breaking the dogma again! Single-crystal X-ray structure analysis of a newly isolated metallofullerene, La2@Cs(17 490)-C76, revealed a cage structure that violates the isolated-pentagon rule (IPR; see figure). More surprisingly, dynamic behavior of the two La3+ ions is observed inside the cage, which conflicts with the common belief that metal cations invariably coordinate strongly with nearby negatively charged fused-pentagon carbons in non-IPR EMFs.

    22. Alkoxycarbonylation

      Catalyst Activity and Selectivity in the Isomerising Alkoxycarbonylation of Methyl Oleate (pages 17131–17140)

      M.Sc. Josefine T. Christl, M.Sc. Philipp Roesle, M.Sc. Florian Stempfle, Dipl.-Chem. Philipp Wucher, Dr. Inigo Göttker-Schnetmann, Prof. Dr. Gerhard Müller and Prof. Dr. Stefan Mecking

      Article first published online: 20 NOV 2013 | DOI: 10.1002/chem.201301124

      Thumbnail image of graphical abstract

      Conversion of plant oils: The selective conversion of plant oils has been studied for a range of diphosphine-coordinated PdII catalysts. An efficient conversion of the double bond deep in the methyl oleate chain to the terminal 1,19-diester (see scheme) was brought about with conveniently accessible α-tolyl-bridged diphosphines. Remarkably, the extreme steric bulk of the diphosphine appears more decisive for the efficient formation of the catalytically active species than for selectivity.

    23. Protein Labeling

      Bioconjugation of Proteins with a Paramagnetic NMR and Fluorescent Tag (pages 17141–17149)

      Feng Huang, Ying-Ying Pei, Hui-Hui Zuo, Jia-Liang Chen, Yin Yang and Prof. Xun-Cheng Su

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201302273

      Thumbnail image of graphical abstract

      Rigid and small: Rigidity and small size of lanthanide-binding tags are critically important in site-specific labeling of proteins with lanthanide ions. 4′-Mercapto-2,2′:6′,2′′-terpyridine-6,6′′-dicarboxylic acid (4MTDA) provides five coordination sites for lanthanide ions and can be readily immobilized by coordination of proteins (see figure).

    24. Enzymatic Catalysis

      Effect of Cation–π Interactions and Steric Bulk on the Catalytic Action of Oxidosqualene Cyclase: A Case Study of Phe728 of β-Amyrin Synthase from Euphorbia tirucalli L (pages 17150–17158)

      Ryousuke Ito, Ippei Hashimoto, Yukari Masukawa and Prof. Dr. Tsutomu Hoshino

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201301917

      Thumbnail image of graphical abstract

      Mutants run wild: The functional analysis of β-amyrin synthase from Euphorbia tirucalli was carried out by constructing the site-specific Ala, Ile, Met, His, and Trp mutants of the wild-type enzyme. The product distribution and enzyme activities estimated in vivo for each of the variants clearly indicate that the Phe728 residue plays a key role in stabilizing intermediary cations 36 (see scheme) through cation–π interactions.

    25. Surface Chemistry

      Outstanding Catalytic Activity of Ultra-Pure Platinum Nanoparticles (pages 17159–17164)

      Aneta Januszewska, Dr. Grzegorz Dercz, Justyna Piwowar, Dr. Rafal Jurczakowski and Dr. Adam Lewera

      Article first published online: 12 NOV 2013 | DOI: 10.1002/chem.201303185

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      Keep it simple! As-received nanoparticles exhibit a threefold increase in catalytic activity compared with nanoparticles synthesized in the presence of a capping agent and subsequently thoroughly electro-oxidatively cleaned (see figure). In these unmodified nanoparticles, an increased surface order is obtained without any surfactant.

    26. Dendrimers

      Interplay of α,α- versus α,β-Conjugation in the Excited States and Charged Defects of Branched Oligothiophenes as Models for Dendrimeric Materials (pages 17165–17171)

      Rafael C. González-Cano, Geeta Saini, Prof. Dr. Josemon Jacob, Prof. Dr. Juan T. López Navarrete, Prof. Dr. Juan Casado and Dr. M. Carmen Ruiz Delgado

      Article first published online: 12 NOV 2013 | DOI: 10.1002/chem.201302244

      Thumbnail image of graphical abstract

      Branching out: Electronic spectroscopies and DFT calculations were used to investigate the excited-state properties and charge delocalization in branched oligothiophenes. A loss of molecular conjugation was found for S0 ground states, whereas more delocalized quinoidal S1 and T1 excited states are formed upon branching (see figure). Delocalization through the α,β-conjugated path is crucial in stabilizing the trication species.

    27. Metal–Organic Frameworks

      Lanthanide Metal–Organic Frameworks Showing Luminescence in the Visible and Near-Infrared Regions with Potential for Acetone Sensing (pages 17172–17179)

      Dr. Song Dang, Xue Min, Dr. Weiting Yang, Dr. Fei-Yan Yi, Prof. Hongpeng You and Prof. Zhong-Ming Sun

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201301346

      Thumbnail image of graphical abstract

      Lighting up time: A family of LnMOFs has been developed (see figure), the members of which show luminescence from the visible to the near-infrared region. Detailed luminescence studies have revealed a potential application for Tb0.08Gd0.92L and Yb0.10Gd0.90L as new fluorescent probes for acetone sensing.

    28. Heterocycles

      Formation of Substituted Oxa- and Azarhodacyclobutanes (pages 17180–17191)

      Alexander Dauth, Carla Rigling, Jennifer Tsoung and Prof. Dr. Jennifer A. Love

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201302421

      Thumbnail image of graphical abstract

      Substitute(d) players: The oxidation of a variety of rhodium complexes bearing substituted olefin ligands by H2O2 and PhINTs is reported. The resulting oxa- and azarhodacyclobutanes are obtained with good-to-excellent regioselectivity (see scheme; Ts=p-toluenesulfonyl). Notably, complementary selectivity for heteroatom incorporation was observed depending on the oxidant employed.

    29. [4]Rotaxanes

      Fluorescence Modulation in Tribranched Switchable [4]Rotaxanes (pages 17192–17200)

      Ji-Na Zhang, Hong Li, Wei Zhou, Shi-Lin Yu, Dr. Da-Hui Qu and Prof. Dr. He Tian

      Article first published online: 7 NOV 2013 | DOI: 10.1002/chem.201303026

      Thumbnail image of graphical abstract

      Switchable rotaxanes: Two novel tribranched [4]rotaxanes with a 1,3,5-triphenylene core and three rotaxane arms have been designed and synthesized (see scheme). Reversible and uniform shuttling motions of three dibenzo[24]crown-8 macrocycles on the molecular threads of these [4]rotaxanes exhibit distinct modes of fluorescence modulation in response to external acid–base stimuli.

    30. Matrix Isolation

      Generation and Spectroscopic Identification of ClCNS, ClNCS and NCCNS (pages 17201–17208)

      Melinda Krebsz, Dr. György Tarczay and Prof. Dr. Tibor Pasinszki

      Article first published online: 6 NOV 2013 | DOI: 10.1002/chem.201302964

      Thumbnail image of graphical abstract

      Three novel pseudohalides, namely, chloronitrile sulfide (ClCNS), chlorine isothiocyanate (ClNCS) and cyanogen N-sulfide (NCCNS) were generated by photolysis of chloro-substituted thiadiazoles in low-temperature, solid-argon matrices and studied by UV and IR spectroscopy (see figure) and quantum chemical calculations.

  7. Correspondence

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Review
    6. Communications
    7. Full Papers
    8. Correspondence
    1. Sonochemical Reductions

      Comment on “Mechanism of PtIV Sonochemical Reduction in Formic Acid Media and Pure Water” (pages 17210–17212)

      Prof. Sara Goldstein and Prof. Dan Meyerstein

      Article first published online: 11 NOV 2013 | DOI: 10.1002/chem.201202958

      Sonochemical formation of Pt0 nanoparticles in formic acid media involves the reduction of PtVI by carboxyl radicals (.CO2H/CO2.−).

    2. Response to Comment on “Mechanism of PtIV Sonochemical Reduction in Formic Acid Media and Pure Water” (pages 17213–17215)

      Dr. Tony Chave and Dr. Sergey I. Nikitenko

      Article first published online: 11 NOV 2013 | DOI: 10.1002/chem.201303042

      Contrary to radiolysis, sonochemistry is not only based on radical processes and further effects such as local activation or heating must be considered in particular for the sonolysis of formic acid. In the same way, the high local concentration of radicals observed in sonochemistry can induce different mechanisms compared to radiolysis.

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