Chemistry - A European Journal

Cover image for Vol. 15 Issue 21

May 18, 2009

Volume 15, Issue 21

Pages 5163–5387

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    8. Correspondence
    9. Preview
    1. Cover Picture: Controlling the Chair Conformation of a Mannopyranose in a Large-Amplitude [2]Rotaxane Molecular Machine (Chem. Eur. J. 21/2009) (page 5163)

      Frédéric Coutrot and Eric Busseron

      Version of Record online: 8 MAY 2009 | DOI: 10.1002/chem.200990073

      Thumbnail image of graphical abstract

      A domino effect from one extremity to the other is observed in a large-amplitude mannosyl [2]rotaxane molecular machine. In their Communication on page 5186 ff., F. Coutrot and E. Busseron describe the efficient preparation of new [2]rotaxane molecular machines containing anilinium and either mono- or disubstituted pyridinium amide stations. In the case of the disubstituted pyridinium amide, the macrocycle shuttles from the anilinium to the pyridinium upon deprotonation and causes an impressive flipping of the chair conformation of the glucidic moiety.

  2. Graphical Abstract

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

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

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    8. Correspondence
    9. Preview
    1. Organic Electronics

      Conformationally Complex π-Conjugated Molecular and Polymeric Materials: New Challenges for Organic Synthesis (pages 5176–5185)

      Daryl A. Guthrie and John D. Tovar

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200900398

      Thumbnail image of graphical abstract

      No protection? A unique, albeit fairly specialized, example of what promises to be a useful retrosynthetic consideration for those designing complex π-molecular systems, namely, using conformation as a protecting group to shield a given reactive site in lieu of protecting-group manipulation, is described (see scheme).

  5. Communications

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    8. Correspondence
    9. Preview
    1. Molecular Machines

      Controlling the Chair Conformation of a Mannopyranose in a Large-Amplitude [2]Rotaxane Molecular Machine (pages 5186–5190)

      Frédéric Coutrot and Eric Busseron

      Version of Record online: 19 FEB 2009 | DOI: 10.1002/chem.200900076

      Thumbnail image of graphical abstract

      Molecular machines boarding now! Molecular machines containing dibenzo[24]crown-8 (DB24C8) and based on an anilinium and a pyridinium amide station have been prepared. The DB24C8 shuttles upon variation of pH and interacts differently with the pyridinium amide station depending on its substitution. When the DB24C8 sits around the disubstituted amide, the conformation of the pyranose changes from 1C4 to 4C1.

    2. Nanolithography

      Enzymatic Nanolithography of Polyaniline Nanopatterns by Using Peroxidase-Modified Atomic Force Microscopy Tips (pages 5191–5194)

      Xiliang Luo, Valber A. Pedrosa and Joseph Wang

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200900433

      Thumbnail image of graphical abstract

      A new enzyme nanolithography strategy for creating conducting polymer nanostructures through the modification of AFM tips with peroxidase is described. Scanning of the modified tip in the presence of aniline and hydrogen peroxide is used for biocatalytic patterning of different polyaniline nanostructures (see figure).

    3. Carbohydrates

      Useful Sialic Acid Modifications Catalyzed by Palladium (pages 5195–5199)

      Chih-Wei Chang, Stéphanie Norsikian and Jean-Marie Beau

      Version of Record online: 7 APR 2009 | DOI: 10.1002/chem.200900093

      Thumbnail image of graphical abstract

      A regio- and stereocontrolled solution for a selective modification at the C-2 or C-4 position of N-acetylneuraminic acid involves the use of allylic substitution catalyzed by palladium. As illustrated in the scheme, regioselective malonylation is under the strict influence of the ligands associated with the allylpalladium complex.

    4. Isocyanate Chemistry

      1,4,2-Diazaphospholidine-3,5-diones and Related Compounds: A Lecture on Unpredictability in Catalysis (pages 5200–5202)

      Frank U. Richter

      Version of Record online: 3 APR 2009 | DOI: 10.1002/chem.200900039

      Thumbnail image of graphical abstract

      Whereas 1-organyl-phospholanes and 1-organyl-2,3-dihydro-1H-phospholes catalyze isocyanate oligomerization, the reaction of isocyanates with 1-organyl-2,5-dihydro-1H-phospholes results in the formation of 1,3-dienes and a novel class of P-heterocycles, 1,4,2-diazaphospholidine-3,5-diones. Isothiocyanates and carbodiimides exhibit analogous behavior. The resultant species readily form P-oxides, P-sulfides (see picture), and quaternary onium salts.

    5. Lanthanoid Clusters

      Lanthaballs: Chiral, Structurally Layered Polycarbonate Tridecanuclear Lanthanoid Clusters (pages 5203–5207)

      Anthony S. R. Chesman, David R. Turner, Boujemaa Moubaraki, Keith S. Murray, Glen B. Deacon and Stuart R. Batten

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200900400

      Thumbnail image of graphical abstract

      New balls please! The viability of using carbonate as the primary anion in cluster formation is demonstrated in the synthesis of ‘lanthaballs’, spherical tridecanuclear lanthanoid complexes with a novel [Ln(CO3)6] moiety in a [Ln13(CO3)14] core (see picture). The chirality of the lanthaballs is evidenced in the configuration of extended columns of π-stacked phenanthroline ligands. The structural and magnetic properties of lanthaballs are investigated.

    6. C[BOND]C Activation

      RhI-Catalyzed Regio- and Stereospecific Carbonylation of 1-(1-Alkynyl)cyclopropyl Ketones: A Modular Entry to Highly Substituted 5,6-Dihydrocyclopenta[c]furan-4-ones (pages 5208–5211)

      Yanqing Zhang, Zuliang Chen, Yuanjing Xiao and Junliang Zhang

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200900413

      Thumbnail image of graphical abstract

      Efficient route: A novel RhI-catalyzed regio- and stereospecific carbonylation reaction of (1-alkynyl)cyclopropyl ketones by selective activation of a carbon[BOND]carbon σ bond of the cyclopropane ring was demonstrated (see scheme). This method provides a general, efficient, stereoselective route to synthesise 1,3,5-trisubstituted and 1,3,5,6-tetrasubstituted 5,6-dihydrocyclopenta[c]furan-4-one with convertible functional groups.

    7. Sensitized Photolysis

      Macrocyclic Disulfides for Studies of Sensitized Photolysis of the S[BOND]S Bond (pages 5212–5214)

      Zhen Huang, Qing-Zheng Yang, Timothy J. Kucharski, Daria Khvostichenko, Steven M. Wakeman and Roman Boulatov

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200900521

      Thumbnail image of graphical abstract

      Sensitized photolysis: We describe a series of macrocyclic disulfides containing stiff stilbene (see scheme) as the intramolecular photosensitizer designed for fundamental mechanistic studies of sensitized photolysis of the S[BOND]S bond. Preliminary studies revealed weak temperature dependence of the quantum yields, which decreased exponentially with Boltzmann-weighted average separation between the S[BOND]S bond and stiff stilbene.

    8. Fluorescence

      Control of the Supramolecular Excimer Formation of Thioflavin T within a Cucurbit[8]uril Host: A Fluorescence On/Off Mechanism (pages 5215–5219)

      Jyotirmayee Mohanty, Sharmistha Dutta Choudhury, Hari P. Upadhyaya, Achikanath C. Bhasikuttan and Haridas Pal

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200802686

      Thumbnail image of graphical abstract

      On or off? A new excimer band at λ=570 nm was visualized during the noncovalent host–guest interaction between thioflavin T (ThT) and cucurbit[8]uril (CB8). Controlled dissociation of this assembly in the presence of Ca2+ was demonstrated as an on/off fluorescence switch (see picture).

  6. Full Papers

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    8. Correspondence
    9. Preview
    1. Ruthenium Catalysis

      Racemization of Alcohols Catalyzed by [RuCl(CO)25-pentaphenylcyclopentadienyl)]—Mechanistic Insights from Theoretical Modeling (pages 5220–5229)

      Jonas Nyhlén, Timofei Privalov and Jan-E. Bäckvall

      Version of Record online: 25 APR 2009 | DOI: 10.1002/chem.200900291

      Thumbnail image of graphical abstract

      Which mechanism? Dissociation of a CO ligand from alkoxide complex 1 to give intermediate 2 seems to be a viable pathway for racemization according to DFT calculations. The highest Gibbs free energy barrier is 22.6 kcal mol−1 for this pathway. Very fast alkoxide exchange can occur in 2 with essentially no barrier. The calculations indicate an alternative low-energy pathway for alkoxide exchange between 1 and 1′ without CO dissociation with a barrier of only 13 kcal mol−1.

    2. Multinary Anions

      Syntheses, Structures, and Comprehensive NMR Spectroscopic Investigations of Hetero-Chalcogenidometallates: The Right Mix toward Multinary Complexes (pages 5230–5244)

      Eugen Ruzin, Eldar Zent, Eberhard Matern, Werner Massa and Stefanie Dehnen

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200802060

      Thumbnail image of graphical abstract

      Library of semiconductors: Mixtures of binary chalcogenidostannate anions in protic solution show statistic chalcogenide exchange (see scheme), which is examined by comprehensive NMR investigations, DFT calculations and chemical reactions. A simple approach is provided to generate a library of semiconductor compounds with finely tuned opto-electronic properties.

    3. Antitumor Agents

      DNA Cross-Linking Patterns Induced by an Antitumor-Active Trinuclear Platinum Complex and Comparison with Its Dinuclear Analogue (pages 5245–5253)

      Jianhui Zhu, Yongmei Zhao, Yanyan Zhu, Ziyi Wu, Miaoxin Lin, Weijiang He, Yan Wang, Guangju Chen, Lei Dong, Junfeng Zhang, Yi Lu and Zijian Guo

      Version of Record online: 6 APR 2009 | DOI: 10.1002/chem.200900217

      Thumbnail image of graphical abstract

      The center of it all: An antitumor-active trinuclear platinum complex forms unprecedented interstrand cross-linked triadducts with 18-mer DNA duplexes (see figure; complex in yellow with the platinum centers in red) and behaves differently from its dinuclear analogue.

    4. Electron-Transfer Mechanisms

      Multiple Mechanisms for Electron Transfer at Metal/Self-Assembled Monolayer/Room-Temperature Ionic Liquid Junctions: Dynamical Arrest versus Frictional Control and Non-Adiabaticity (pages 5254–5262)

      Dimitri E. Khoshtariya, Tina D. Dolidze and Rudi van Eldik

      Version of Record online: 2 APR 2009 | DOI: 10.1002/chem.200802450

      Thumbnail image of graphical abstract

      When all the mechanisms go marching in: Electrochemical devices consisting of Au electrodes coated by self-assembled alkanethiol monolayers of variable thickness, a ferrocene/ferrocenium redox probe and [bmim][NTf2] (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) as the solvent (see picture), under variable overvoltage, temperature and pressure conditions, allowed the disclosure of three different electron-transfer patterns.

    5. Gallium Chemistry

      Synthesis, Characterization and Real Molecule DFT Calculations for Neutral Organogallium(I) Aryl Dimers and Monomers: Weakness of Gallium[BOND]Gallium Bonds in Digallenes and Digallynes (pages 5263–5272)

      Zhongliang Zhu, Roland C. Fischer, Bobby D. Ellis, Eric Rivard, W. Alexander Merrill, Marilyn M. Olmstead, Philip P. Power, J. D. Guo, Shigeru Nagase and Lihung Pu

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200900201

      Thumbnail image of graphical abstract

      Move closer: The gallium[BOND]gallium bond strength in terphenyl gallium(I) dimers [ArGaGaAr] (see figure) is similar to those in other molecules with closed shell interactions, implying that the Ga[BOND]Ga bond in doubly reduced Na2[ArGaGaAr] is much closer to a single than a triple one.

    6. Supramolecular Chemistry

      Lanthanide-Based Coordination Polymers Assembled by a Flexible Multidentate Linker: Design, Structure, Photophysical Properties, and Dynamic Solid-State Behavior (pages 5273–5288)

      Claire Marchal, Yaroslav Filinchuk, Xiao-Yan Chen, Daniel Imbert and Marinella Mazzanti

      Version of Record online: 31 MAR 2009 | DOI: 10.1002/chem.200802589

      Thumbnail image of graphical abstract

      Flexible director: A flexible multidentate linker containing picolinate chromophores directs the selective formation of luminescent 1D lanthanide-based polymers. Partial protonation significantly decreases the preorganization of the linker, thus leading to supramolecular 1D and 2D isomers (see scheme). The lanthanide-containing 1D polymers undergo reversible structural modification in the hydration/dehydration process, which is also associated with significant differences in the luminescence emission.

    7. Reaction Mechanisms

      Rhodium(I)-Catalysed Intramolecular [2+2+2] Cyclotrimerisations of 15-, 20- and 25-Membered Azamacrocycles: Experimental and Theoretical Mechanistic Studies (pages 5289–5300)

      Anna Dachs, Anna Torrent, Anna Roglans, Teodor Parella, Sílvia Osuna and Miquel Solà

      Version of Record online: 22 APR 2009 | DOI: 10.1002/chem.200802548

      Thumbnail image of graphical abstract

      Number of members makes a difference: The [2+2+2] intramolecular cyclotrimerisation of a new series of 20- and 25-membered azamacrocycles catalysed by the Wilkinson's catalyst are reported (see scheme). The 20- and 25-membered azamacrocycles show different reactivity. Why? Theoretical calculations give insight into the reactivity differences observed for the 20- and 25-membered macrocycles.

    8. Light-Harvesting Systems

      Synthesis and Photoinduced Intramolecular Processes of Light-Harvesting Silicon Phthalocyanine–Naphthalenediimide–Fullerene Connected Systems (pages 5301–5310)

      Mohamed E. El-Khouly, Jung Hoon Kim, Kwang-Yol Kay, Chan Soo Choi, Osamu Ito and Shunichi Fukuzumi

      Version of Record online: 3 APR 2009 | DOI: 10.1002/chem.200900165

      Thumbnail image of graphical abstract

      Fast moving: A new pentad (see figure) composed of silicon phthalocyanine (SiPc), as electron donor, that is connected with two units of naphthalenediimide (NDI) and fullerene C60, as electron acceptors, undergoes fast and efficient charge-separation processes via the NDI and SiPc singlet excited states.

    9. Phosphors

      Sr5Al5+xSi21−xN35−xO2+x:Eu2+ (x≈0)—A Novel Green Phosphor for White-Light pcLEDs with Disordered Intergrowth Structure (pages 5311–5319)

      Oliver Oeckler, Juliane A. Kechele, Hans Koss, Peter J. Schmidt and Wolfgang Schnick

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200802645

      Thumbnail image of graphical abstract

      A novel sialon phosphor is characterized by an unusual silicate framework, built up of edge- and vertex-sharing tetrahedra (orange and green). Owing to pronounced pseudotranslations, the compound is highly disordered. It was investigated in detail by X-ray diffraction and electron microscopy. Despite the disorder, all Sr atoms (yellow spheres) exhibit very similar coordination spheres, and doping with Eu2+ results in efficient green luminescence (see inset; Em.=emission, Exc.=excitation, Refl.=reflection).

    10. Tunable Mesoporous Materials

      Controllable Synthesis of Mesoporous Co3O4 Nanostructures with Tunable Morphology for Application in Supercapacitors (pages 5320–5326)

      Shenglin Xiong, Changzhou Yuan, Xiaogang Zhang, Baojuan Xi and Yitai Qian

      Version of Record online: 6 APR 2009 | DOI: 10.1002/chem.200802671

      Thumbnail image of graphical abstract

      Flower power: Various mesoporous Co3O4 architectural structures (see figure) have been successfully prepared through a facile binary-solution route and sequential thermal decomposition at atmospheric pressure. The electrochemical experiments showed that the specific capacitance of Co3O4 nanosheets was higher than that of Co3O4 microspheres in a KOH electrolyte.

    11. Ligand–Receptor Interactions

      Mapping Receptor Density on Live Cells by Using Fluorescence Correlation Spectroscopy (pages 5327–5336)

      Yan Chen, Alina C. Munteanu, Yu-Fen Huang, Joseph Phillips, Zhi Zhu, Michael Mavros and Weihong Tan

      Version of Record online: 9 APR 2009 | DOI: 10.1002/chem.200802305

      Thumbnail image of graphical abstract

      Sensitive surveying: Fluorescence correlation spectroscopy (FCS) was used to study receptor density and to monitor ligand–receptor interactions on live cell membranes by the introduction of fluorescently marked aptamers, which specifically bind to certain cell-surface receptors (see schematic representation; FITC: fluorescein isothiocyanate).

    12. Dendrimers

      Diffusion and NOE NMR Studies on Multicationic DAB-Organoruthenium Dendrimers: Size-Dependent Noncovalent Self-Assembly to Megamers and Ion Pairing (pages 5337–5347)

      Stefania Pettirossi, Gianfranco Bellachioma, Gianluca Ciancaleoni, Cristiano Zuccaccia, Daniele Zuccaccia and Alceo Macchioni

      Version of Record online: 6 APR 2009 | DOI: 10.1002/chem.200802585

      Thumbnail image of graphical abstract

      Supra-mega ion pairing: Multicationic organoruthenium dendrimers show a notable tendency to self-aggregate when the concentration is increased, leading to megamers. This tendency increases with the generation. The self-aggregation of dendrimers to megamers is coupled with a decrease in the extent of ion pairing, as illustrated.

    13. Molecular Sieves

      New Insights into the Role of Amines in the Synthesis of Molecular Sieves in Ionic Liquids (pages 5348–5354)

      Renshun Xu, Weiping Zhang, Jing Guan, Yunpeng Xu, Lei Wang, Huaijun Ma, Zhijian Tian, Xiuwen Han, Liwu Lin and Xinhe Bao

      Version of Record online: 26 MAR 2009 | DOI: 10.1002/chem.200802590

      Thumbnail image of graphical abstract

      In a new direction: In situ NMR spectroscopy and DFT calculation studies demonstrate that the hybrid of imidazolium ionic liquids with morpholine can be formed by means of hydrogen bonds during the crystallization of molecular sieves (see graphic; T=Al or P), which drastically alters the structure-directing property.

    14. Microporous Materials

      Investigation of the Ion Storage/Transfer Behavior in an Electrical Double-Layer Capacitor by Using Ordered Microporous Carbons as Model Materials (pages 5355–5363)

      Hirotomo Nishihara, Hiroyuki Itoi, Taichi Kogure, Peng-Xiang Hou, Hidekazu Touhara, Fujio Okino and Takashi Kyotani

      Version of Record online: 31 MAR 2009 | DOI: 10.1002/chem.200802406

      Thumbnail image of graphical abstract

      Ordered microporous carbon: The mechanism of an electrical double-layer capacitor containing zeolite-templated carbons as model microporous materials was investigated in detail (see figure). Its three-dimensionally ordered and connected micropores were found to greatly reduce ion-transfer resistance and, therefore, exhibited a high rate performance.

    15. Oxidation

      Efficient Oxidation of 1,2-Diols into α-Hydroxyketones Catalyzed by Organotin Compounds (pages 5364–5370)

      Toshihide Maki, Shinya Iikawa, Gen Mogami, Hitomi Harasawa, Yoshihiro Matsumura and Osamu Onomura

      Version of Record online: 6 APR 2009 | DOI: 10.1002/chem.200900159

      Thumbnail image of graphical abstract

      Get selective! A selective oxidation of 1,2-diols to α-hydroxyketones catalyzed by organotin compounds has been developed (see scheme). Invaluable chemo- and stereoselectivity were found in the reaction. The catalytic system has been achieved by electrochemical and chemical oxidation.

  7. Correspondence

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

      The Folly of Protobranching: Turning Repulsive Interactions into Attractive Ones and Rewriting the Strain/Stabilization Energies of Organic Chemistry (pages 5372–5382)

      Scott Gronert

      Version of Record online: 29 APR 2009 | DOI: 10.1002/chem.200800282

      Thumbnail image of graphical abstract

      Strain/stabilization energies: Recently it has been argued that the accepted strain/stabilization energies of fundamental species are incorrect because they ignore the effects of protobranching. Here it is shown that the basic premise of the protobranching mechanism is unlikely and that conventional strain/stabilization energies are more chemically important than those from the protobranching approach.

  8. Preview

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    8. Correspondence
    9. Preview
    1. You have free access to this content
      Preview: Chem. Eur. J. 22/2009 (page 5387)

      Version of Record online: 11 MAY 2009 | DOI: 10.1002/chem.200990076

SEARCH

SEARCH BY CITATION