Chemistry - A European Journal

Cover image for Chemistry - A European Journal

September 3, 2010

Volume 16, Issue 33

Pages 9925–10259

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
    1. Cover Picture: Chemistry and Biology of the Caged Garcinia Xanthones (Chem. Eur. J. 33/2010) (page 9925)

      Oraphin Chantarasriwong, Ayse Batova, Warinthorn Chavasiri and Emmanuel A. Theodorakis

      Article first published online: 26 AUG 2010 | DOI: 10.1002/chem.201090163

      Thumbnail image of graphical abstract

      Garcinia trees have been used throughout the years as sources of medicines, pigments, gums, waxes, resins, foodstuffs (fruit), fuel (wood, seed oil), and lumber. For instance, the yellow colorant used on 8th century artifacts from East Asia (as shown in the picture) is presumed to be a watercolor based on gamboge, the pulverized gold-colored resin collected primarily from Garcinia hanburyi. In their Review on page 9944 ff., E. A. Theodorakis et al. describe a family of compounds derived from gambogic acid with respect to their structures and biological activities.

  2. Graphical Abstract

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
    1. Graphical Abstract: Chem. Eur. J. 33/2010 (pages 9928–9937)

      Article first published online: 26 AUG 2010 | DOI: 10.1002/chem.201090164

  3. Corrigendum

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
    1. You have free access to this content
  4. News

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
  5. Review

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
    1. Natural Products

      Chemistry and Biology of the Caged Garcinia Xanthones (pages 9944–9962)

      Oraphin Chantarasriwong, Ayse Batova, Warinthorn Chavasiri and Emmanuel A. Theodorakis

      Article first published online: 20 JUL 2010 | DOI: 10.1002/chem.201000741

      Thumbnail image of graphical abstract

      Golden discovery: Gamboge, the golden resin of various Garcinia trees, has a spectacular history in traditional Asian medicine. Chemical analysis of gamboge led to the identification of a new family of bioactive metabolites collectively referred to as caged Garcinia xanthones. Represented by gambogic acid (see figure), this family is highlighted by a privileged chemical scaffold that holds remarkable potential in chemistry, biology, and medicine.

  6. Communications

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
    1. Metal-Mediated Synthesis

      You have full text access to this OnlineOpen article
      Synergic Transformation of an Ethylenediamine to a Lithium 1,3-Diaza-2-zincacyclopentene via an Alkyllithium/Bis(alkyl)zinc Mixture (pages 9964–9968)

      Ross Campbell, Pablo García-Álvarez, Alan R. Kennedy and Robert E. Mulvey

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201001314

      Thumbnail image of graphical abstract

      Deadly duo: Four bonds in total, two N[BOND]H and two C[BOND]H bonds, have been cleaved from a neutral secondary diamine through the cooperative effects of a lithium alkyl–zinc bisalkyl coalition aided by N,N,N′,N′-tetramethylethylenediamine (TMEDA) to generate a dianionic diazaethene (see scheme).

    2. Asymmetric Catalysis

      The Magnesium(II)-Catalyzed Asymmetric Ketone–Ene Reaction under Solvent-Free Conditions: Stereocontrolled Access to Enantioenriched Trifluoromethyl-Substituted Compounds (pages 9969–9972)

      Ke Zheng, Yang Yang, Jiannan Zhao, Chengkai Yin, Lili Lin, Xiaohua Liu and Xiaoming Feng

      Article first published online: 21 JUL 2010 | DOI: 10.1002/chem.201001412

      Thumbnail image of graphical abstract

      Salt of the (alkaline) earth: A highly efficient asymmetric ketone–ene reaction of trifluoropyruvate catalyzed by a chiral Mg(OTf)2N,N′-dioxide complex is described (see scheme). The catalyst system exhibits a broad substrate scope and the trifluoromethylated α-hydroxy esters were obtained under solvent-free conditions. The C[DOUBLE BOND]C bond of the products offers a handle for further transformations and trifluoromethyl-substituted spirocyclic compounds were synthesized in excellent ee and high yield.

    3. Oxidation

      Oxidation of α-Alkoxy Allenes into α′-Alkoxy Enones (pages 9973–9976)

      Pierre Cordier, Corinne Aubert, Max Malacria, Vincent Gandon and Emmanuel Lacôte

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000914

      Thumbnail image of graphical abstract

      Rearrangement enablers: α-Alkoxy allenes undergo regioselective oxidative migration to give α′-alkoxy enones in good to excellent yields (see scheme; Bn=benzyl, mCPBA=m-chloroperbenzoic acid). The influence of substituents on the allene, at C1, and at the oxygen atom has been examined. In addition, an oxidative cascade delivers α′-alkoxy oxiranyl ketones through diepoxidation.

    4. Mesoporous Materials

      Synthesis of Highly Stable and Crystalline Mesoporous Anatase by Using a Simple Surfactant Sulfuric Acid Carbonization Method (pages 9977–9981)

      Renyuan Zhang, Bo Tu and Dongyuan Zhao

      Article first published online: 21 JUL 2010 | DOI: 10.1002/chem.201001241

      Thumbnail image of graphical abstract

      Highly stable and crystalline mesoporous TiO2 materials have been successfully synthesized by a simple surfactant sulfuric acid carbonization method by using Pluronic triblock copolymers as a template (see figure). The surfactant template is first carbonized by H2SO4 to obtain rigid carbon on the surface of mesochannels that can then support the mesostructure during crystallization at high temperatures.

    5. Cross-Coupling

      Palladium-Catalyzed Sonogashira Coupling of Aryl Mesylates and Tosylates (pages 9982–9985)

      Pui Ying Choy, Wing Kin Chow, Chau Ming So, Chak Po Lau and Fuk Yee Kwong

      Article first published online: 21 JUL 2010 | DOI: 10.1002/chem.201001269

      Thumbnail image of graphical abstract

      Up to speed: The first general and mild protocol for the Sonogashira coupling of aryl mesylates is presented (see scheme). The coupling intermediate also provides facile access to 2-substituted isoquinolines.

    6. A General Palladium-Catalyzed Sonogashira Coupling of Aryl and Heteroaryl Tosylates (pages 9986–9989)

      Omar R'kyek, Nis Halland, Andreas Lindenschmidt, Jorge Alonso, Peter Lindemann, Matthias Urmann and Marc Nazaré

      Article first published online: 6 JUL 2010 | DOI: 10.1002/chem.201001524

      Thumbnail image of graphical abstract

      Coupled up: A new general palladium-catalyzed procedure for the cross-coupling of aryl and heteroaryl tosylates is described. This highly versatile and efficient process can be used for the synthesis of a wide variety of functionalized alkynes (see scheme).

    7. Coordination Frameworks

      Reversible Phase Transformation and Luminescent Mechanochromism of ZnII-Based Coordination Frameworks Containing a Dipyridylamide Ligand (pages 9990–9993)

      Biing-Chiau Tzeng, Tsung-Yi Chang and Hwo-Shuenn Sheu

      Article first published online: 15 JUL 2010 | DOI: 10.1002/chem.201001346

      Thumbnail image of graphical abstract

      It's all in the grinding: A 1D double-zigzag framework, {[Zn(paps)2(H2O)2](ClO4)2}n, was synthesized by the reaction of Zn(ClO4)2 with paps (see structure in scheme) in a layer method. A similar reaction, but in which dry solvents were used instead, led to the formation of a 2D polyrotaxane framework, [Zn(paps)2(ClO4)2]n. Both structures can be interconverted by heating and grinding in the presence of moisture and a remarkable luminescent mechanochromism in the transformation process is also observed by monitoring their luminescence images.

    8. Magnetic Properties

      Crystal-to-Crystal Transformation from a Mononuclear Compound in a Hydrogen-Bonded Three-Dimensional Framework to a Layered Coordination Polymer (pages 9994–9997)

      Bin Zhang, Daoben Zhu and Yan Zhang

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201001398

      Thumbnail image of graphical abstract

      Out of the blue: Blue crystals composed of a mononuclear compound in a hydrogen-bonded three-dimensional framework (1) can be transformed into brown crystals composed of a layered coordination polymer (2) by desolvation (see figure). These crystal-to-crystal transformations result in changes in the dimensionality, color, and physical properties.

  7. Full Papers

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
    1. Coordination Chemistry

      Cobalt Coordination and Clustering in α-Co(OH)2 Revealed by Synchrotron X-ray Total Scattering (pages 9998–10006)

      James R. Neilson, Joshua A. Kurzman, Ram Seshadri and Daniel E. Morse

      Article first published online: 2 AUG 2010 | DOI: 10.1002/chem.201000661

      Thumbnail image of graphical abstract

      Local structure—cobalt clustering: The structures of layered hydroxides are not well described by traditional crystallography. Total scattering of a particular subset of these materials reveals that different cobalt coordination polyhedra cluster within each layer (see graphic) on short length scales, offering new insights into approaches for understanding the properties of layered materials.

    2. Nanocatalysts

      In Situ Formation of Au–Pd Bimetallic Active Sites Promoting the Physically Mixed Monometallic Catalysts in the Liquid-Phase Oxidation of Alcohols (pages 10007–10013)

      Di Wang, Alberto Villa, Paolo Spontoni, Dang Sheng Su and Laura Prati

      Article first published online: 12 JUL 2010 | DOI: 10.1002/chem.201001330

      Thumbnail image of graphical abstract

      Active alloys: Starting from a physical mixture of Au/AC and Pd/AC catalysts (AC=activated carbon), an Au–Pd alloy can be formed during the liquid-phase oxidation of alcohols by reprecipitation of Pd onto Au nanoparticles (see images). The alloy formation greatly enhances the catalyst activity.

    3. Polyoxometalates

      High-Field Pulsed EPR Spectroscopy for the Speciation of the Reduced [PV2Mo10O40]6− Polyoxometalate Catalyst Used in Electron-Transfer Oxidations (pages 10014–10020)

      Ilia Kaminker, Hila Goldberg, Ronny Neumann and Daniella Goldfarb

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000944

      Thumbnail image of graphical abstract

      A band apart: A W-band EPR study of [PVIVVVMo10O40]6− was carried out. Two species related to [PVIVVVMo10O40]6− were identified. One is vanadyl (VO2+)-like and is represented as an ion pair, [PVVMo10O39]8−[VIVO]2+; the other originates from reduction of distal H5PV2Mo10O40 isomers to yield an intact cluster, [PVIVVVMo10O40]6− (see graphic).

    4. Delocalised States

      Multichromophoric Phthalocyanine–(Perylenediimide)8 Molecules: A Photophysical Study (pages 10021–10029)

      Sebastian Albert-Seifried, Chris E. Finlayson, Frederic Laquai, Richard H. Friend, Timothy M. Swager, Paul H. J. Kouwer, Michal Juríček, Heather J. Kitto, Sanne Valster, Roeland J. M. Nolte and Alan E. Rowan

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000677

      Thumbnail image of graphical abstract

      Eight is better than one: Photophysical characterisation of a series of novel phthalocyanine–perylene “octad” molecules shows rapid energy transfer, rather than the anticipated charge separation process, upon photoexitation (see figure).

    5. Fluorinated Inhibitors

      3-Fluoroaspartate and Pyruvoyl-Dependant Aspartate Decarboxylase: Exploiting the Unique Characteristics of Fluorine To Probe Reactivity and Binding (pages 10030–10041)

      Jandré de Villiers, Lizbé Koekemoer and Erick Strauss

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000622

      Thumbnail image of graphical abstract

      Caught in a trap! The two L-isomers of 3-fluoroaspartate were synthesized and used to probe pyruvoyl-dependent aspartate decarboxylase enzymes. Our results show that these molecules maintain their unique conformations (as determined by the presence of fluorine) even in the active site of these enzymes, leading to differentiated reactivity and binding profiles and, in one case, a stable enzyme/product complex (see figure).

    6. Photocatalysis

      Highly Efficient Visible Light Plasmonic Photocatalyst Ag@Ag(Br,I) (pages 10042–10047)

      Peng Wang, Baibiao Huang, Qianqian Zhang, Xiaoyang Zhang, Xiaoyan Qin, Ying Dai, Jie Zhan, Jiaoxian Yu, Haixia Liu and Zaizhu Lou

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.200903361

      Thumbnail image of graphical abstract

      Let there be light: The plasmonic photocatalyst Ag@Ag(Br,I) has been fabricated by the ion-exchange process and light-induced chemical reduction reaction. The photocatalytic properties of the sample were evaluated by photoreducing CrVI and photooxidizing methylic orange (MO) under visible light (reaction arrows in red and green refer to two separate processes).

    7. Hybrid Materials

      Fatty Acid Carboxylate- and Anionic Surfactant-Controlled Delivery Systems That Use Mesoporous Silica Supports (pages 10048–10061)

      Carmen Coll, Elena Aznar, Ramón Martínez-Máñez, M. Dolores Marcos, Félix Sancenón, Juan Soto, Pedro Amorós, Joan Cano and Eliseo Ruiz

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.200903125

      Thumbnail image of graphical abstract

      Taking control: MCM-41 mesoporous materials have been prepared that contain [Ru(bipy)3]Cl2 (bipy=bipyridine) inside the mesopores and anion binding groups (i.e., imidazolium, urea and thiourea) in the pore outlets. The delivery of these materials in the presence of long-chain carboxylate ions and anionic surfactants has been studied. Molecular dynamic simulations that use force-field methods have been made to theoretically study the capping carboxylate mechanism (see scheme).

    8. Molecular Machines

      Bistable or Oscillating State Depending on Station and Temperature in Three-Station Glycorotaxane Molecular Machines (pages 10062–10073)

      Eric Busseron, Camille Romuald and Frédéric Coutrot

      Article first published online: 6 JUL 2010 | DOI: 10.1002/chem.201000777

      Thumbnail image of graphical abstract

      Three molecular stations with different affinity for dibenzo[24]crown-8 (DB24C8) are present in the glycorotaxane molecular machines shown schematically in the picture. At low pH, DB24C8 resides around the best anilinium station, whereas at higher pH, the macrocycle behaves very differently depending on the substitution of the pyridinium amide station and on the temperature (bistable or oscillating state).

    9. Spin Crossover

      Coordination-Induced Spin Crossover (CISCO) through Axial Bonding of Substituted Pyridines to Nickel–Porphyrins: σ-Donor versus π-Acceptor Effects (pages 10074–10083)

      Steffen Thies, Claudia Bornholdt, Felix Köhler, Frank D. Sönnichsen, Christian Näther, Felix Tuczek and Rainer Herges

      Article first published online: 20 JUL 2010 | DOI: 10.1002/chem.201000603

      Thumbnail image of graphical abstract

      In a spin: Nickel–porphyrin (R=C6F5) coordinates two axial pyridine ligands upon changing from the S=0 to the S=1 state. The association constants of both steps correlate with the pKa of the pyridines but the binding enthalpies and entropies do not. Back donation from nickel to the electron-deficient pyridines (see picture) leads to an increase in association enthalpy and a shift of IR stretching frequencies in the corresponding pyridines to lower wavenumbers.

    10. Supramolecular Chemistry

      Self-Sorted Assembly in a Mixture of Donor and Acceptor Chromophores (pages 10084–10093)

      Mijanur Rahaman Molla, Anindita Das and Suhrit Ghosh

      Article first published online: 25 JUN 2010 | DOI: 10.1002/chem.201000596

      Thumbnail image of graphical abstract

      Self-assembly in a true sense: Self-sorted assembly in a mixture of bis-amide-functionalised donor and acceptor chromophores has been achieved due to the synergistic effect of π–π stacking and hydrogen bonding. Remarkable differences in the mode of self-assembly (self-sorting vs. donor–acceptor π stacking, see figure) was noticed, depending on the position of the amide functionalities with respect to the individual chromophores.

    11. Contrast Agents

      Cyclodextrin-Based Bimodal Fluorescence/MRI Contrast Agents: An Efficient Approach to Cellular Imaging (pages 10094–10102)

      Zuzana Kotková, Jan Kotek, Daniel Jirák, Pavla Jendelová, Vít Herynek, Zuzana Berková, Petr Hermann and Ivan Lukeš

      Article first published online: 25 JUN 2010 | DOI: 10.1002/chem.200903519

      Thumbnail image of graphical abstract

      Dual probes for cellular imaging: A novel bimodal medium-sized fluorescence/MRI probe based on a cyclodextrin scaffold has been synthesized and characterized (illustrated schematically here). This new GdIII contrast agent, exhibiting a high relaxivity confined to a small molecular space (r1≈150 s−1 mM−1 per molecule of contrast agent), has been successfully used for the imaging of pancreatic islets and stem cells.

    12. Quantum Clusters

      Luminescent Quantum Clusters of Gold in Bulk by Albumin-Induced Core Etching of Nanoparticles: Metal Ion Sensing, Metal-Enhanced Luminescence, and Biolabeling (pages 10103–10112)

      Madathumpady Abubaker Habeeb Muhammed, Pramod Kumar Verma, Samir Kumar Pal, Archana Retnakumari, Manzoor Koyakutty, Shantikumar Nair and Thalappil Pradeep

      Article first published online: 7 JUL 2010 | DOI: 10.1002/chem.201000841

      Thumbnail image of graphical abstract

      The Midas touch: Core etching of gold nanoparticles by bovine serum albumin (BSA) results in quantum clusters (QCs), the luminescence of which (see picture) is exploited as a “turn-off” sensor for the detection of Cu2+ ions and a “turn-on” sensor for glutathione detection. Metal-enhanced luminescence of the QCs occurs in the presence of silver nanoparticles. The luminescence of AuQC@BSA is used for imaging carcinoma cells by folic acid mediated endocytosis.

    13. Nanosorbents

      Redox Sorption and Recovery of Silver Ions as Silver Nanocrystals on Poly(aniline-co-5-sulfo-2-anisidine) Nanosorbents (pages 10113–10123)

      Xin-Gui Li, Hao Feng and Mei-Rong Huang 

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000506

      Thumbnail image of graphical abstract

      Silver mining: Aniline–sulfoanisidine copolymer nanosorbents demonstrate ultrastrong adsorbability and highly efficient recovery of AgI from waste water in the form of separable silver nanocrystals, turning trash into treasure. The maximal AgI sorption capacity of 2034 mg g−1 (18.86 mmol g−1) is the highest so far, and at ≤2 mM AgI, the nanosorbent exhibits ≥99.98 % AgI adsorptivity. The picture shows the possible sorption mechanism, as well as XRD and microscopy evidence for the presence of elemental silver in the Ag-loaded nanosorbent.

    14. Asymmetric Synthesis

      Efficient Synthesis of β-Hydroxy-α-Amino Acid Derivatives via Direct Catalytic Asymmetric Aldol Reaction of α-Isothiocyanato Imide with Aldehydes (pages 10124–10129)

      Xiaohong Chen, Yin Zhu, Zhen Qiao, Mingsheng Xie, Lili Lin, Xiaohua Liu and Xiaoming Feng

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000284

      Thumbnail image of graphical abstract

      A nickel for your thoughts: A chiral N,N′-dioxide–nickel(II) complex has been applied in the asymmetric direct aldol reaction of α-isothiocyanato imide with aldehydes. A series of aromatic, α,β-unsaturated, heteroaromatic, and aliphatic aldehydes were converted into the desired β-hydroxy-α-amino acid derivatives under mild conditions (see scheme). A possible transition state has been proposed.

    15. Asymmetric Catalysis

      Highly Enantioselective Synthesis of α-Stereogenic Esters through Catalytic Asymmetric Michael Addition of 4-Oxo-4-arylbutenoates (pages 10130–10136)

      Zhen Wang, Donghui Chen, Zhigang Yang, Sha Bai, Xiaohua Liu, Lili Lin and Xiaoming Feng

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201001129

      Thumbnail image of graphical abstract

      Add it up: Highly enantioselective Michael addition of 1,3-dicarbonyl compounds and nitromethane to 4-oxo-4-arylbutenoates catalyzed by N,N′-dioxide–Sc(OTf)3 complexes have been developed (see scheme). Various α-stereogenic esters were obtained regioselectively with excellent yields and enantioselectivities under mild conditions.

    16. Homogeneous Catalysis

      Do Trinuclear Triplesalen Complexes Exhibit Cooperative Effects? Synthesis, Characterization, and Enantioselective Catalytic Sulfoxidation by Chiral Trinuclear FeIII Triplesalen Complexes (pages 10137–10149)

      Chandan Mukherjee, Anja Stammler, Hartmut Bögge and Thorsten Glaser

      Article first published online: 14 JUL 2010 | DOI: 10.1002/chem.201000923

      Thumbnail image of graphical abstract

      Complex chemistry: The reaction of the trinuclear chiral triplesalen complex [(FeCl)3(chandRR)] in the enantioselective catalytic sulfoxidation of prochiral sulfides has altered cooperative effects through the central phloroglucinol backbone relative to the mononuclear analogue [FeCl(salen′)].

    17. Total Synthesis

      Formal Total Synthesis of Fostriecin by 1,4-Asymmetric Induction with an Alkyne–Cobalt Complex (pages 10150–10159)

      Yujiro Hayashi, Hirofumi Yamaguchi, Maya Toyoshima, Kotaro Okado, Takumi Toyo and Mitsuru Shoji 

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000795

      Thumbnail image of graphical abstract

      CoCo catalysis: Four stereogenic centers and a conformationally labile cis-cis-trans-triene moiety were constructed in a formal total synthesis of fostriecin. The synthesis incorporates the first successful example of the use of an alkyne–cobalt complex in 1,4-asymmetric induction.

    18. Bonding Analysis

      Carbodicarbenes and Related Divalent Carbon(0) Compounds (pages 10160–10170)

      Susanne Klein, Ralf Tonner and Gernot Frenking

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000174

      Thumbnail image of graphical abstract

      Carbene or carbone? Quantum-chemical studies on dicoordinated carbon compounds with various mono- and bidentate ligands (see picture) show that there is a gliding scale between the bonding situation of carbenes R[BOND]C[BOND]R, in which the carbon atom has one electron pair, and carbones L→C←L, in which the carbon atom has two electron pairs. Divalent carbon(0) compounds (carbones) CL2 are π donors, whereas divalent carbon(II) compounds (carbenes) CR2 are π acceptors.

    19. Radical Reactions

      Synthesis of Unusual Oxime Ethers by Reaction of Tetranitromethane with B-Alkylcatecholboranes (pages 10171–10177)

      Monique Lüthy, Kurt Schenk and Philippe Renaud

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000680

      Thumbnail image of graphical abstract

      Radical addition: B-Alkylcatecholboranes were found to react spontaneously, through a radical pathway, with tetranitromethane to afford dinitrooxime ethers. Further substitution of one of the nitro groups in the oxime ethers by alkyl radicals and nucleophiles is also reported (see scheme).

    20. Magnetic Properties

      Magnetic Properties of Two New Fe4 Single-Molecule Magnets in the Solid State and in Frozen Solution (pages 10178–10185)

      Christoph Schlegel, Enrique Burzurí, Fernando Luis, Fabrizio Moro, Maria Manoli, Euan K. Brechin, Mark Murrie and Joris van Slageren

      Article first published online: 9 JUL 2010 | DOI: 10.1002/chem.200903505

      Thumbnail image of graphical abstract

      Frozen magnetisation: The relaxation time of Fe4 single-molecule magnets increases upon going from the solid state to a frozen solution. The effective energy barrier for relaxation of the magnetisation and the magnetic anisotropy are unchanged, but the Arrhenius prefactor is strongly enhanced.

    21. Nanobioreactors

      Real-Time Monitoring of Mass-Transport-Related Enzymatic Reaction Kinetics in a Nanochannel-Array Reactor (pages 10186–10194)

      Su-Juan Li, Chen Wang, Zeng-Qiang Wu, Jing-Juan Xu, Xing-Hua Xia and Hong-Yuan Chen

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000318

      Thumbnail image of graphical abstract

      Enhancement through confinement: A nano-enzyme reactor has been constructed that can monitor the product from an enzymatic reaction in situ (see scheme; Glu=glucose, GOD=glucose oxidase, PAA=porous anodic alumina). The activity and stability of the enzyme confined in the nanochannel space are enhanced. In addition, the enzymatic reaction changes from a process controlled by mass transport at low flux to a process controlled by enzymatic reaction kinetics at high flux (e.g., >50 μL min−1).

    22. Host–Guest Catalysis

      New Phosphane Based on a β-Cyclodextrin, Exhibiting a Solvent-Tunable Conformation, and its Catalytic Properties (pages 10195–10201)

      Cécile Machut-Binkowski, François-Xavier Legrand, Nathalie Azaroual, Sébastien Tilloy and Eric Monflier

      Article first published online: 30 JUN 2010 | DOI: 10.1002/chem.201000379

      Thumbnail image of graphical abstract

      Solvent-dependent catalysis: A new diphenylphosphane, based on the β-cyclodextrin (CD) skeleton, exhibits dual solubility and a solvent-dependent conformation change in which the self-inclusion of a phenyl group of the phosphane moiety into the CD cavity, observed in water, disappears in organic solvents (see scheme). Hydrogenation or hydroformylation reactions were performed in both water and organic solvents.

    23. Click Chemistry

      Complexes of Click-Derived Bistriazolylpyridines: Remarkable Electronic Influence of Remote Substituents on Thermodynamic Stability as well as Electronic and Magnetic Properties (pages 10202–10213)

      Marc Ostermeier, Marie-Anne Berlin, Robert M. Meudtner, Serhiy Demeshko, Franc Meyer, Christian Limberg and Stefan Hecht

      Article first published online: 23 JUL 2010 | DOI: 10.1002/chem.201000721

      Thumbnail image of graphical abstract

      Turning the knob: 2,6-Bis(1,2,3-triazol-4-yl)pyridine (see figure) ligands with substitution patterns ranging from strongly electron-donating to strongly electron-accepting groups, readily prepared by means of Cu-catalyzed 1,3-dipolar cycloaddition (“click” reaction), were investigated with regard to their complexation behavior, and the properties of the resulting transition-metal complexes were compared.

    24. Alkaloids

      The Conformational Landscape of Nicotinoids: Solving the Conformational Disparity of Anabasine (pages 10214–10219)

      Alberto Lesarri, Emilio J. Cocinero, Luca Evangelisti, Richard D. Suenram, Walther Caminati and Jens-Uwe Grabow

      Article first published online: 9 JUL 2010 | DOI: 10.1002/chem.201000849

      Thumbnail image of graphical abstract

      Nicotinoid stereochemistry: The two most stable conformations of free anabasine (eq-eq-syn, left, and eq-eq-anti, right; eq=equatorial) have been characterized in a jet expansion by using rotational spectroscopy.

    25. Nanowires

      Single-Crystalline ZnO Nanowire Bundles: Synthesis, Mechanism and Their Application in Dielectric Composites (pages 10220–10225)

      Guangsheng Wang, Yuan Deng and Lin Guo

      Article first published online: 29 JUN 2010 | DOI: 10.1002/chem.200902973

      Thumbnail image of graphical abstract

      A facile synthesis route has been designed for selective syntheses of uniform single-crystalline ZnO nanowire bundles (see figure). The ZnO bundles/poly(vinylidene fluoride) composites have significantly higher dielectric constants than those of bulk ZnO/ poly(vinylidene fluoride) with a quite low percolation threshold.

    26. Self-Assembly

      Selective Lanthanides Sequestration Based on a Self-Assembled Organosilica (pages 10226–10233)

      Eric Besson, Ahmad Mehdi, Arie Van der Lee, Hervé Chollet, Catherine Reyé, Roger Guilard and Robert J. P. Corriu

      Article first published online: 6 JUL 2010 | DOI: 10.1002/chem.200902454

      Thumbnail image of graphical abstract

      A bis-zwitterionic lamellar material containing ammonium carboxylate groups was tested for cation-exchange properties. It was found to be selective towards lanthanides; cation uptake was dependent on the nature of the LnCl3 salt (Ln=La, Eu, Tb, Er and Yb; see figure).

    27. Nanotechnology

      Facile Synthesis of Ag Nanocubes of 30 to 70 nm in Edge Length with CF3COOAg as a Precursor (pages 10234–10239)

      Qiang Zhang, Weiyang Li, Long-Ping Wen, Jingyi Chen and Younan Xia

      Article first published online: 30 JUN 2010 | DOI: 10.1002/chem.201000341

      Thumbnail image of graphical abstract

      New protocol: We describe a new protocol to synthesize Ag nanocubes of 30 to 70 nm in edge length (see figure) with the use of CF3COOAg as a precursor to elemental silver. By adding a trace amount of NaSH and HCl to the polyol synthesis, Ag nanocubes were obtained with good quality, high reproducibility, and on a scale of up to 0.19 g per batch for the 70 nm Ag nanocubes.

    28. Radical Reactions

      Selective Reductions of Cyclic 1,3-Diesters by Using SmI2 and H2O (pages 10240–10249)

      Karl D. Collins, Juliana M. Oliveira, Giuditta Guazzelli, Brice Sautier, Sara De Grazia, Hiroshi Matsubara, Madeleine Helliwell and David J. Procter

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000632

      Thumbnail image of graphical abstract

      Under water control: The activation of SmI2 with H2O allows the carbonyl groups of cyclic 1,3-diesters to be reduced with high chemoselectivity. The radicals formed in the reduction have been exploited in diastereoselective intramolecular additions to alkenes.

    29. Hydrosilylation

      Hydrosilylation of a Silicon(II) Hydride: Synthesis and Characterization of a Remarkable Silylsilylene (pages 10250–10254)

      Shu-Hua Zhang, Hui-Xian Yeong, Hong-Wei Xi, Kok Hwa Lim and Cheuk-Wai So

      Article first published online: 19 JUL 2010 | DOI: 10.1002/chem.201000089

      Thumbnail image of graphical abstract

      Silylsilylenes on rare form: Monomeric silylsilylene 2 was synthesized by treating 1 with potassium graphite. The reaction proceeds through an intermediate silicon(II) hydride that undergoes a hydrosilylation with the amidinate of another silicon(II) hydride to form 2 (see scheme). The existence of the silicon(II) hydride was shown by the treatment of [{PhC(NtBu)2}SiCl] with [K{HB(iBu)3}]. The structure of 2 has been determined by X-ray crystallography and DFT calculations.

  8. Preview

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Corrigendum
    5. News
    6. Review
    7. Communications
    8. Full Papers
    9. Preview
    1. You have free access to this content
      Preview: Chem. Eur. J. 34/2010 (page 10259)

      Article first published online: 26 AUG 2010 | DOI: 10.1002/chem.201090162

SEARCH

SEARCH BY CITATION