Angewandte Chemie International Edition

Cover image for Vol. 44 Issue 35

September 5, 2005

Volume 44, Issue 35

Pages 5535–5749

    1. Cover Picture: A T-Shaped Platinum(II) Boryl Complex as the Precursor to a Platinum Compound with a Base-Stabilized Borylene Ligand (Angew. Chem. Int. Ed. 35/2005) (page 5535)

      Holger Braunschweig, Krzysztof Radacki, Daniela Rais and David Scheschkewitz

      Article first published online: 1 SEP 2005 | DOI: 10.1002/anie.200590117

      Cationic T-shaped platinum complexes are obtained because of the high trans influence of the ferrocenyl(bromo)boryl ligand. Addition of 4-methylpyridine to the platinum(II) boryl complex (as shown in the cover picture) causes displacement of the bromide ion at boron, leading to a cationic platinum complex with a 4-methylpyridine-stabilized borylene ligand (bottom right). For more information on this approach, see the Communication by H. Braunschweig et al. on page 5651 ff.

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    3. Graphical Abstract: Angew. Chem. Int. Ed. 35/2005 (pages 5543–5553)

      Article first published online: 1 SEP 2005 | DOI: 10.1002/anie.200590118

    4. Organocopper for the Craftsman Cunning at His Trade (pages 5560–5562)

      Simon Woodward

      Article first published online: 29 JUL 2005 | DOI: 10.1002/anie.200501204

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      The organocopper craftsman's toolset is nearly complete with recent advances in ligand-based catalytic organocopper chemistry, which make viable enantioselective 1,4-conjugate additions and SN2′ substitutions of allylic halides using Grignard, RZnCl, and organoaluminum reagents (see scheme) at low loadings of copper(I) salts.

    5. A Revolution in Electron Microscopy (pages 5563–5566)

      John Meurig Thomas

      Article first published online: 26 JUL 2005 | DOI: 10.1002/anie.200501466

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      Ultrafast electron microscopy is a versatile technique that allows images and diffraction patterns of crystalline and amorphous materials as well as images of biological cells to be measured (see picture). Advances in the domain of time-resolved electron microscopy and the potential of the technique in various applications are discussed.

    6. Chemicals with Endocrine-Disrupting Potential: A Threat to Human Health? (pages 5568–5574)

      Helmut Greim

      Article first published online: 1 SEP 2005 | DOI: 10.1002/anie.200502138

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      Horror scenarios have been conjured up, but how harmful, really, are the hormone-like compounds with which we come into contact daily in food, medications, and sunscreens? A xenobiotic can compete with a hormone at the hormone receptor and even block its action, as the picture shows for the estrogen receptor. To cause an observable effect, however, the potency and concentration of the xenobiotic must be sufficiently high, which fortunately is rarely the case.

    7. Mesocrystals: Inorganic Superstructures Made by Highly Parallel Crystallization and Controlled Alignment (pages 5576–5591)

      Helmut Cölfen and Markus Antonietti

      Article first published online: 20 JUL 2005 | DOI: 10.1002/anie.200500496

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      Nonclassical Crystallization: Mesocrystals are superstructures of well-aligned nanoparticles, which exhibit common outer faces on the mm or μm scale (see picture, right: SEM image of dl-alanine). They are usually built up from nonspherical nanoparticles which allows for further degrees of orientational freedom so that only very little is known about mesocrystal formation. Mesocrystals are examples of nonclassical crystallization, which were only recently discovered.

    8. The Chemistry of Organic Nanomaterials (pages 5592–5629)

      Andrew C. Grimsdale and Klaus Müllen

      Article first published online: 1 SEP 2005 | DOI: 10.1002/anie.200500805

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      Smaller and better: Thanks to recent progress in organic nanomaterials, functional building blocks based on single molecules or small ensembles of molecules are no longer just the realm of science fiction, but are a realistically attainable goal. The picture shows the different organization steps of functional molecules, from a dendrimer, to a “nanopropeller”, to nanotubes.

    9. Asymmetric Vacuum UV photolysis of the Amino Acid Leucine in the Solid State (pages 5630–5634)

      Uwe J. Meierhenrich, Laurent Nahon, Christian Alcaraz, Jan Hendrik Bredehöft, Søren V. Hoffmann, Bernard Barbier and André Brack

      Article first published online: 20 JUL 2005 | DOI: 10.1002/anie.200501311

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      One hand clapping: Based on solid-state circular dichroism data, the leucine (π*, π1)-electronic transition is excited with right circularly polarized synchrotron radiation (r-CPSR) at 182 nm (see scheme). This treatment induced an enantiomeric excess of 2.6 % of D-leucine. The results support the assumption that interstellar asymmetric photoreactions are capable of inducing significant enantiomeric enrichments in solid-state amino acids.

    10. Ultrafast Solvation of N-Methyl-6-quinolone Probes Local IR Spectrum (pages 5635–5639)

      J. Luis Pérez Lustres, Sergey A. Kovalenko, Manuel Mosquera, Tamara Senyushkina, Wolfgang Flasche and Nikolaus P. Ernsting

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200501397

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      A molecular dipole field (see picture) is created by femtosecond excitation of the title compound, and the response of the environment is observed by stimulated emission spectroscopy of the dye. Strong frequency modulation in the dynamic Stokes shift reflects coherent solvent motion. The IR spectrum of the solvent is related quantitatively to the experiment by dielectric continuum theory.

    11. Energetics and Mechanism of a Room-Temperature Catalytic Process for Ammonia Synthesis (Schrock Cycle): Comparison with Biological Nitrogen Fixation (pages 5639–5642)

      Felix Studt and Felix Tuczek

      Article first published online: 5 AUG 2005 | DOI: 10.1002/anie.200501485

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      The transformation of N2to 2 NH3 on a MoIII complex containing a sterically shielding triamidoamine ligand is investigated with the help of DFT calculations, providing the energy profile and mechanism of the first truly catalytic process of ammonia synthesis working under ambient conditions and proceeding via well-defined intermediates (see catalytic cycle). It is shown that ammonia synthesis with this artificial system works with an energy expenditure comparable to that of biological nitrogen fixation.

    12. Studying the Solvothermal Formation of MoO3 Fibers by Complementary In Situ EXAFS/EDXRD Techniques (pages 5643–5647)

      Alexej Michailovski, Jan-Dierk Grunwaldt, Alfons Baiker, Ragnar Kiebach, Wolfgang Bensch and Greta R. Patzke

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200500514

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      Just a minute: The hydrothermal formation of fibrous MoO3 is monitored with complementary in situ methods. The quantitative formation is complete within a few minutes, as shown by in situ EDXRD investigations (see picture: time-dependent powder diffractograms at 120 °C). A special in situ EXAFS cell permits the simultaneous observation of the solid and the liquid phase, thereby providing key information about the growth mechanism of the MoO3 rods.

    13. Synthesis of ansa-[2]Boracyclopentadienylcycloheptatrienylchromium and Its Reaction to the ansa-Platinabis(boryl) Complex by Oxidative Addition of the Boron[BOND]Boron Bond (pages 5647–5651)

      Holger Braunschweig, Matthias Lutz and Krzysztof Radacki

      Article first published online: 13 JUL 2005 | DOI: 10.1002/anie.200500686

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      Chromium sandwich with “handles”: A [2]boratrochrocenophane with diboron bridges was synthesized and oxidatively added to [Pt(PEt3)4]. The resulting [3]boraplatinatrochrocenophane, which is the first example of an ansa-[3]boraplatina sandwich complex, was characterized in solution and in the solid state.

    14. A T-Shaped Platinum(II) Boryl Complex as the Precursor to a Platinum Compound with a Base-Stabilized Borylene Ligand (pages 5651–5654)

      Holger Braunschweig, Krzysztof Radacki, Daniela Rais and David Scheschkewitz

      Article first published online: 1 SEP 2005 | DOI: 10.1002/anie.200501588

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      “T” time: A cationic, three-coordinate T-shaped platinum boryl complex (see structure) serves as the precursor to a cationic platinum complex featuring a base-stabilized borylene ligand.

    15. Theoretical and Experimental Evidence for a New Kind of Spin-Coupled Singlet Species: Isomeric Mixed-Valent Complexes Bridged by a Radical Anion Ligand (pages 5655–5658)

      Biprajit Sarkar, Srikanta Patra, Jan Fiedler, Raghavan B. Sunoj, Deepa Janardanan, Shaikh M. Mobin, Mark Niemeyer, Goutam Kumar Lahiri and Wolfgang Kaim

      Article first published online: 3 AUG 2005 | DOI: 10.1002/anie.200501075

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      Valencies get remix: A unique kind of electronic structure (Mn+0.5)(μ-L.−)(Mn+0.5) which was previously discussed only for metal–ligand charge-transfer (MLCT) excited states is established structurally and by quantum chemical analysis for both rac (see picture) and meso isomers of [(μ-abpy){Ru(acac)2}2] (abpy=2,2′-azobispyridine, acac=acetylacetonate).

    16. Unusual Solubility Properties of Polymethacrylamides as a Result of Supramolecular Interactions with Cyclodextrin (pages 5658–5661)

      Sarah Schmitz and Helmut Ritter

      Article first published online: 29 JUL 2005 | DOI: 10.1002/anie.200501374

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      Clearing things up. Hydrophobic polymers that undergo complex formation with β-cyclodextrin in aqueous solution display reversible thermosensitive solubility. Supramolecular effects lead to a new kind of LCST behavior (LCST=lower critical solution temperature), which is evident from clouding and clearing points at defined temperatures (see picture). The polymer was synthesized by free-radical polymerization of the complexed monomer in water.

    17. An Aldimine Cross-Coupling for the Diastereoselective Synthesis of Unsymmetrical 1,2-Diamines (pages 5662–5664)

      Coralie Kison, Nino Meyer and Till Opatz

      Article first published online: 29 JUL 2005 | DOI: 10.1002/anie.200501705

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      No protecting groups are required for the cross-coupling of N-monosubstituted α-aminonitriles with imines. Depending on the workup procedure, highly substituted unsymmetrical 1,2-diamines or 1,2-diimines can be prepared in a one-pot procedure. The diastereoselective reduction of the diimines furnishes either the syn- or the anti-configurated diamines (see scheme).

    18. Versatile Direct Synthesis of Oligosubstituted Pyrroles by Cycloaddition of α-Metalated Isocyanides to Acetylenes (pages 5664–5667)

      Oleg V. Larionov and Armin de Meijere

      Article first published online: 24 AUG 2005 | DOI: 10.1002/anie.200502140

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      Acceptor-substituted pyrroles can be prepared from acetylenes and isocyanides in an efficient and direct manner by a formal cycloaddition under basic conditions or, even simpler, in the presence of catalytic amounts of nanosize copper powder or copper(I) benzenethiolate.

    19. Synthesis of Thermolabile Zinc–Pentel Compounds under Kinetically Controlled Reaction Conditions (pages 5668–5670)

      Florian Thomas, Stephan Schulz and Martin Nieger

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200500688

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      Base-stabilized aluminum–pentel compounds [(dmap)Al(Me2)E(SiMe3)2] (dmap=4-dimethylaminopyridine; E=P, As, Sb) are valuable reagents for the synthesis of zinc–pentel heterocycles of the type [{MeZnE(SiMe3)2}3]. In addition, a novel Zn–Sb cluster was structurally characterized (see structure; blue Sb, red Zn, yellow Cl, green Si). The reactions proceed at low temperature, an essential factor for the synthesis of these thermolabile compounds.

    20. Models of Putative (AH)G(AH)G Nucleobase Quartets (pages 5670–5674)

      Pilar Amo-Ochoa, Pablo J. Sanz Miguel, Patrick Lax, Inés Alonso, Michael Roitzsch, Félix Zamora and Bernhard Lippert

      Article first published online: 5 AUG 2005 | DOI: 10.1002/anie.200500896

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      Mispairs of protonated adenine and guanine (or hypoxanthine), AH+anti G/Hxsyn, can associate in various ways to give mixed purine quartets (see picture) as demonstrated by X-ray crystallography and ab initio calculations. The planar structure of such quartets implies that akin to established purine nucleobase quartets, these quartets could also play a role in natural DNA structures.

    21. Photo-Cross-Coupling Reaction of Electron-Rich Aryl Chlorides and Aryl Esters with Alkynes: A Metal-Free Alkynylation (pages 5675–5678)

      Stefano Protti, Maurizio Fagnoni and Angelo Albini

      Article first published online: 5 AUG 2005 | DOI: 10.1002/anie.200501541

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      Photoheterolysis of aryl halides substituted with electron-donating groups (EDGs) or aryl esters in 2,2,2-trifluoroethanol (TFE) leads to phenyl cations, which can add to alkynes (see scheme, Tf=trifluoromethanesulfonyl). This reaction is an appealing metal-free alternative to the (sila)-Sonogashira reaction.

    22. A Functional Assay for Heparin in Serum Using a Designed Synthetic Receptor (pages 5679–5682)

      Aaron T. Wright, Zhenlin Zhong and Eric V. Anslyn

      Article first published online: 5 AUG 2005 | DOI: 10.1002/anie.200501437

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      Excellent selectivity in highly competitive serum was displayed by a synthetic fluorescent receptor incorporating phenylboronic acid and ammonium groups for the therapeutic anticoagulant heparin. The concentration of heparin at clinically relevant dosing levels can be measured from the emission quenching. The binding is reversible as shown by the regeneration of the fluorescence on addition of protamine (see graph).

    23. Modeling the Anodic Half-Cell of a Low-Temperature Coal Fuel Cell (pages 5682–5686)

      Douglas B. Weibel, Roman Boulatov, Andrew Lee, Rosaria Ferrigno and George M. Whitesides

      Article first published online: 5 AUG 2005 | DOI: 10.1002/anie.200501192

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      Mined over matter: The partial oxidation of sub-bituminous coal by FeIII ions in 5 M H2SO4 at 100 °C was used in the anodic compartment in a prototype coal fuel cell, with a solution of VO2+/VO2+ in 5 M H2SO4 in the cathodic compartment (see scheme). The cell operated without loss of performance for 1000 h at 100 °C, with a maximum current density of 5 A L−1 and a power density of 0.6 W L−1.

    24. Tailored Catalytic Propene Trimerization over Acidic Zeolites with Tubular Pores (pages 5687–5690)

      Johan A. Martens, Wim H. Verrelst, Georges M. Mathys, Stephen H. Brown and Pierre A. Jacobs

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200463045

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      Slim through spatial constraints: A higher content of linear and monobranched propene trimers is obtained with ZSM-22 as catalyst than with many other zeolite catalysts (see picture). This is explained by the constraints imposed by the diameter of the tubular pores of ZSM-22. ZSM-22 also brings an important environmental benefit compared with the presently used industrial catalyst silica-supported phosphoric acid.

    25. The First Structure of a Cerium(IV) Phosphate: Ab Initio Rietveld Analysis of CeIV(PO4)(HPO4)0.5(H2O)0.5 (pages 5691–5694)

      Micaela Nazaraly, Gilles Wallez, Corinne Chanéac, Elisabeth Tronc, François Ribot, Michel Quarton and Jean-Pierre Jolivet

      Article first published online: 3 AUG 2005 | DOI: 10.1002/anie.200501871

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      Layer apparent: Crystalline cerium(IV) phosphates have been studied for a long time as ion exchangers, but their structures have remained unknown. The structure of a cerium(IV) phosphate has been determined (see picture: tetrahedra PO4, yellow Ce, blue O (water)) and clearly explains a notable feature of this compound, its inability to intercalate amines. The X-ray study is supported by solid-state NMR spectroscopy investigations.

    26. Current Oscillations during Formic Acid Oxidation on a Pt Electrode: Insight into the Mechanism by Time-Resolved IR Spectroscopy (pages 5694–5698)

      Gabor Samjeské and Masatoshi Osawa

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200501009

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      Revised model: Current oscillations in the electrooxidation of formic acid at a fixed potential can be observed by time-resolved surface-enhanced infrared absorption spectroscopy (see picture). Real-time probing of the reaction dynamics on the electrode surface provides new insight into the oscillations that are not accessible by conventional techniques. The reaction mechanism involves adsorbed formate as a reactive intermediate.

    27. Preparation of a Hydroperoxo Zinc(II) Intermediate (pages 5698–5701)

      Akira Wada, Syuhei Yamaguchi, Koichiro Jitsukawa and Hideki Masuda

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200501157

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      Three legs and four teeth: The tripodal tetradentate ligand bis[(6-neopentylamino-2-pyridyl)methyl][(2-pyridyl)methyl]amine (H2bnpa) was used to prepare a novel {Zn[BOND]OOH} species. The intermediate of the reaction of [Zn(H2bnpa)(OH)]+ with H2O2 (see scheme) was characterized by a combination of 1H NMR spectroscopy and ESI mass spectrometry; further treatment with CO2 gave [{Zn2+(H2bnpa)}2(CO42−)](ClO4)2.

    28. Redox Control of Light-Induced Platinum-Cluster-to-Iron Charge Transfer in a Bis(ferrocenylethynyl)-Substituted Hexanuclear Platinum Derivative (pages 5701–5705)

      Alberto Albinati, Fabrizia Fabrizi de Biani, Piero Leoni, Lorella Marchetti, Marco Pasquali, Silvia Rizzato and Piero Zanello

      Article first published online: 4 AUG 2005 | DOI: 10.1002/anie.200501714

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      Give and take: Compound 1 (see structure: purple Pt, red Fe, green P, blue O; Fc=[(η-C5H5)Fe(η-C5H4)]) is prepared in good yields by the CuI-catalyzed coupling of two equivalents of ethynylferrocene with the hexanuclear cluster [Pt6(μ-PtBu2)4(CO)4Cl2]. Electrochemical and spectroelectrochemical data show the presence of photoelectrochemically triggered electron transfer from the {Pt6} core to the peripheral ferrocenyl subunits.

    29. Stable Cyclic (Alkyl)(Amino)Carbenes as Rigid or Flexible, Bulky, Electron-Rich Ligands for Transition-Metal Catalysts: A Quaternary Carbon Atom Makes the Difference (pages 5705–5709)

      Vincent Lavallo, Yves Canac, Carsten Präsang, Bruno Donnadieu and Guy Bertrand

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200501841

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      Like NHCs? Not quite: Cyclic (alkyl)(amino)carbenes (CAACs) are strong σ-donors and have steric environments that differ dramatically from those of bulky, electron-rich phosphines (A) and cyclic diaminocarbenes (B). These readily available carbenes are desirable ligands for catalysis, as illustrated by the first palladium-mediated α-arylation of ketones and aldehydes with non-activated aryl chlorides at ambient temperature.

    30. Methyl-Blocked Dimeric α,γ-Peptide Nanotube Segments: Formation of a Peptide Heterodimer through Backbone–Backbone Interactions (pages 5710–5713)

      Roberto J. Brea, Manuel Amorín, Luis Castedo and Juan R. Granja

      Article first published online: 4 AUG 2005 | DOI: 10.1002/anie.200501555

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      Cyclic peptides can dimerize through β-sheet-like hydrogen bonding. Heterodimerization is favored over homodimerization, which creates interesting combinatorial possibilities without detriment to the functionalization of amino acid side chains. These dimers represent a new class of self-assembling peptide nanotubes in which the hydrophobicity of the internal cavity (see picture) can be controlled.

    31. A Ligation and Photorelease Strategy for the Temporal and Spatial Control of Protein Function in Living Cells (pages 5713–5717)

      Jean-Philippe Pellois and Tom W. Muir

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200501244

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      Design and light: A photocleavable synthetic moiety is ligated to the C terminus of a recombinant protein. In the ligated state, the chemical and protein components influence the properties of one another. Upon irradiation with light, both elements are released and their respective function is recovered. In this way a protein can be delivered into living cells and activated by UV irradiation at a desired time or location.

    32. Lewis Base Promoters in the Pauson–Khand Reaction: A Different Scenario (pages 5717–5719)

      Carlos Perez del Valle, Anne Milet, Yves Gimbert and Andrew E. Greene

      Article first published online: 3 AUG 2005 | DOI: 10.1002/anie.200500955

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      Irreversiblity effect: The fundamental role of Lewis base promoters L in the Pauson–Khand reaction was studied by DFT calculations. Contrary to the currently held view, these promoters do not accelerate the departure of a second CO ligand from the acetylene dicobalt complex to create the requisite site for olefin coordination, but stabilize the olefin-insertion product (see scheme), so that product formation is essentially irreversible.

    33. A Synthetic Zwitterionic Water Channel: Characterization in the Solid State by X-ray Crystallography and NMR Spectroscopy (pages 5720–5725)

      Zhaofu Fei, Dongbin Zhao, Tilmann J. Geldbach, Rosario Scopelliti, Paul J. Dyson, Sasa Antonijevic and Geoffrey Bodenhausen

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200500207

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      Nanoscale plumbing: A zwitterionic, helical pipe of nanodimensions that contains a two-dimensional water chain (see picture; Br yellow, C gray, N blue, O red, Hwater white, Himidazolium omitted) assembles from the reaction between zinc metal and N,N′-diacetic acid imidazolium bromide. A detailed study on the dynamics of the incorporated water molecules has been conducted by solid-state NMR spectroscopy.

    34. F⋅⋅⋅H[BOND]N Hydrogen Bonding Driven Foldamers: Efficient Receptors for Dialkylammonium Ions (pages 5725–5729)

      Chuang Li, Shi-Fang Ren, Jun-Li Hou, Hui-Ping Yi, Shi-Zheng Zhu, Xi-Kui Jiang and Zhan-Ting Li

      Article first published online: 3 AUG 2005 | DOI: 10.1002/anie.200500982

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      Intramolecular F⋅⋅⋅H[BOND]N hydrogen bonds have been utilized for the first time to construct a new series of foldamers from aromatic amides (see picture; R1=H, Me; R2=CON(n-C8H17)2). Moreover, the resulting crescent and helical architectures are good acceptors for binding dialkylammonium ions.

    35. Inverse Coordination of an Ionic Lattice by a Metal Host (pages 5729–5733)

      Melinda J. Duer, Felipe García, Richard A. Kowenicki, Vesal Naseri, Mary McPartlin, Matthew L. Stead, Robin S. Stein and Dominic S. Wright

      Article first published online: 3 AUG 2005 | DOI: 10.1002/anie.200501198

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      The solid-state structure of Li+[{MeAl(PPh)3Li4}44-Cl)(thf)12] (see picture) dramatically illustrates the concept of lattice modification by “inverse” coordination of anions in an ionic lattice. A large change in the original NaCl-type lattice of LiCl results from the encapsulation of the Cl ions within heterometallic cages formed from four [MeAl(PPh)3Li4] inverse ligands.

    36. Hydrogen-Bonded Supramolecular Assemblies as Robust Templates in the Synthesis of Large Metal-Coordinated Capsules (pages 5733–5736)

      Robert M. McKinlay, Praveen K. Thallapally, Gareth W. V. Cave and Jerry L. Atwood

      Article first published online: 4 AUG 2005 | DOI: 10.1002/anie.200501491

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      Uncommon water chain: A large neutral hexameric coordination cage [Ga12(H2O)24(C40H42O12)6⊂(acetone)8(H2O)6] is assembled from six pyrogallol[4]arene ligands and twelve GaIII ions. Found within the capsule structure are two pseudo-linear hydrogen-bonded water (H2O)5 chains (see picture, Ga gold, O red).

    37. Targeting Nucleic Acid Secondary Structures with Polyamides Using an Optimized Dynamic Combinatorial Approach (pages 5736–5739)

      Sylvain Ladame, Andrew M. Whitney and Shankar Balasubramanian

      Article first published online: 3 AUG 2005 | DOI: 10.1002/anie.200501450

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      Reversible disulfide chemistry is used to identify ligands that stabilize either duplex or quadruplex DNA secondary structures from a dynamic combinatorial library of polyamide building blocks (example structure shown). Double-stranded DNA induces a larger amplification than quadruplex DNA, in accordance with the selectivity of the ligands for each DNA target.

    38. Supermolecular Control of Charge Transfer in Dye-Sensitized Nanocrystalline TiO2 Films: Towards a Quantitative Structure–Function Relationship (pages 5740–5744)

      Saif A. Haque, Samantha Handa, Katja Peter, Emilio Palomares, Mukundan Thelakkat and James R. Durrant

      Article first published online: 1 AUG 2005 | DOI: 10.1002/anie.200500363

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      A trial separation: A dye-sensitized nanocrystalline TiO2 film (see scheme) is prepared in which a remarkably long-lived (4 s) charge-separated state can be generated. The key parameter that controls charge transfer at the dye/TiO2 interface is shown to be the spatial separation between the cation center of the dye and the electrode surface.

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      Preview: Angew. Chem. Int. Ed. 35/2005 (page 5749)

      Article first published online: 1 SEP 2005 | DOI: 10.1002/anie.200590119

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