Chemistry - A European Journal

Cover image for Vol. 19 Issue 44

October 25, 2013

Volume 19, Issue 44

Pages 14737–15056

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    1. You have free access to this content
      Cover Picture: Titanium Nitride Nanocrystals on Nitrogen-Doped Graphene as an Efficient Electrocatalyst for Oxygen Reduction Reaction (Chem. Eur. J. 44/2013) (page 14737)

      Dr. Mengjia Liu, Dr. Youzhen Dong, Dr. Yongmin Wu, Dr. Hongbin Feng and Prof. Dr. Jinghong Li

      Article first published online: 16 OCT 2013 | DOI: 10.1002/chem.201390174

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      An efficient electrocatalyst for the oxygen reduction reaction (ORR) based on a TiN/nitrogen-doped graphene hybrid, generated through facile grain nucleation and growth of titanium nitride (TiN) nanoparticles on simultaneously generated nitrogen-doped graphene (NG) sheets under ammonia annealing, is described by J. Li et al. in their Full Paper on p. 14781 ff. Oxygen and water molecules react on the hybrid in a four-electron pathway. Experimental results indicate that the excellent catalytic activity is ascribed to the synergistic chemical coupling effects between TiN and NG.

    2. You have free access to this content
      Inside Cover: ZnSe Etching of Zn-Rich Cu2ZnSnSe4: An Oxidation Route for Improved Solar-Cell Efficiency (Chem. Eur. J. 44/2013) (page 14738)

      Simón López-Marino, Yudania Sánchez, Dr. Marcel Placidi, Andrew Fairbrother, Moisés Espindola-Rodríguez, Xavier Fontané, Dr. Víctor Izquierdo-Roca, Dr. Juan López-García, Dr. Lorenzo Calvo-Barrio, Prof. Dr. Alejandro Pérez-Rodríguez and Dr. Edgardo Saucedo

      Article first published online: 16 OCT 2013 | DOI: 10.1002/chem.201390175

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      Chemistry for a cleaner energy: Se-rich kesterites are highly promising materials for low cost thin-film photovoltaic technologies. The best devices rely on absorbers grown under Zn-rich and Cu-poor conditions. These off-stoichiometric conditions favor the presence of a ZnSe secondary phase, which is detrimental for device performance. Thus, its effective selective removal is necessary to improve the absorber quality. In their Full Paper on page 14814 ff. Saucedo et al. present a new oxidizing route to ensure efficient removal of ZnSe using KMnO4 in H2SO4 acid, followed by an aqueous Na2S solution treatment.

    3. You have free access to this content
      Back Cover: Electrospun Hierarchical CaCo2O4 Nanofibers with Excellent Lithium Storage Properties (Chem. Eur. J. 44/2013) (page 15060)

      Linlin Li, Dr. Shengjie Peng, Yanling Cheah, Yahwen Ko, Peifen Teh, Grace Wee, Dr. Chuiling Wong and Prof. Madhavi Srinivasan

      Article first published online: 16 OCT 2013 | DOI: 10.1002/chem.201390178

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      Hierarchical CaCo2O4 nanofibers  constructed by thin nanoplates have been successfully prepared by a simple and convenient electrospinning technique as described by S. Peng, M. Srinivasan et al. in their Full Paper on page 14823 ff. The morphology of 1D CaCo2O4 nanostructures can be easily controlled by rationally adjusting the calcination temperature. As potential anode materials for lithium ion batteries, hierarchical CaCo2O4 nanofibers exhibit an excellent cycling performance and rate capability.

  2. Graphical Abstract

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    1. Graphical Abstract: Chem. Eur. J. 44/2013 (pages 14741–14751)

      Article first published online: 16 OCT 2013 | DOI: 10.1002/chem.201390176

  3. News

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

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    1. Chemical Concepts

      On Two Different Objectives of the Concepts of Ionic Radii (pages 14758–14767)

      Jian-Biao Liu, Prof. Dr. W. H. Eugen Schwarz and Prof. Dr. Jun Li

      Article first published online: 19 SEP 2013 | DOI: 10.1002/chem.201300917

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      Different concepts for atomic radii are obtained through different types of partitioning molecules into atoms. The transferable Goldschmidt–Shannon-type radii are beneficial for compound classification, prediction and understanding of structures. The non-transferable topological Bader-type bonded radii (see figure) are different toward different neighbors and are indicators of the atomic environment. Both non-overlapping atomic models can be understood with the help of the overlapping atoms model.

  5. Communications

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    1. Medicinal Chemistry

      DMSO-Mediated Ligand Dissociation: Renaissance for Biological Activity of N-Heterocyclic-[Ru(η6-arene)Cl2] Drug Candidates (pages 14768–14772)

      Dr. Malay Patra, Dr. Tanmaya Joshi, Vanessa Pierroz, Dr. Katrin Ingram, Marcel Kaiser, Priv.-Doz. Dr. Stefano Ferrari, Priv.-Doz. Dr. Bernhard Spingler, Prof. Dr. Jennifer Keiser and Prof. Dr. Gilles Gasser

      Article first published online: 2 OCT 2013 | DOI: 10.1002/chem.201303341

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      Slipped under the radar? 1H NMR spectroscopic examination revealed that [Ru(η6-arene)Cl2(L)] (L=N-heterocyclic ligands) complexes readily undergo a ligand exchange reaction in DMSO (see scheme), a popular medium for preparing stock solutions for biological screening. It is therefore highly important for researchers to study the stability in DMSO before reporting on the biological activity of such complexes.

    2. C[BOND]H Activation

      N,N′-Diamidocarbenes Facilitate Selective C[BOND]H Insertions and Transfer Hydrogenations (pages 14773–14776)

      Jonathan P. Moerdyk and Prof. Christopher W. Bielawski

      Article first published online: 2 OCT 2013 | DOI: 10.1002/chem.201302691

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      C[BOND]H bound: Diamidocarbenes were found to facilitate highly selective C[BOND]H bond activation in hydrocarbons containing benzylic, allylic, or α-carbonyl positions. Mechanistic studies showed a preference for intramolecular C[BOND]H insertion for C[BOND]H bonds at more substituted carbon atoms, whereas intermolecular insertions were enabled by relatively electron-deficient substrates. The diamidocarbenes also promoted metal- and additive-free transfer hydrogenations.

    3. Semiconductors

      Efficient Separation of Photogenerated Electron-Hole Pairs by the Combination of a Heterolayered Structure and Internal Polar Field in Pyroelectric BiOIO3 Nanoplates (pages 14777–14780)

      Wenjun Wang, Prof. Dr. Baibiao Huang, Xiangchao Ma, Zeyan Wang, Xiaoyan Qin, Xiaoyang Zhang, Prof. Dr. Ying Dai and Prof. Dr. Myung-Hwan Whangbo

      Article first published online: 2 OCT 2013 | DOI: 10.1002/chem.201302884

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      Electrify your chemistry! Pyroelectric heterolayered BiOIO3 nanoplates efficiently separate photogenerated electron-hole pairs due to the combined effect of their heterolayered structure and internal polar field (see scheme). Pyroelectric BiOIO3 nanoplates, synthesized by a simple hydrothermal method, were found to possess a superior photocatalytic activity under UV irradiation.

    4. Oxygen Reduction

      Titanium Nitride Nanocrystals on Nitrogen-Doped Graphene as an Efficient Electrocatalyst for Oxygen Reduction Reaction (pages 14781–14786)

      Dr. Mengjia Liu, Dr. Youzhen Dong, Dr. Yongmin Wu, Dr. Hongbin Feng and Prof. Dr. Jinghong Li

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201302425

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      Through a facile synthetic process, a TiN/NG hybrid can be prepared as an efficient oxygen reduction reaction electrocatalyst in a four-electron pathway (see figure). It is low-cost and widely available and affords strong methanol tolerance and long-term durability. The synergistic chemical coupling effects between TiN and NG should be responsible for the excellent catalytic activity.

    5. Cycloadditions

      An Efficient Gold-Catalyzed Domino Process for the Construction of Tetracyclic Ketoethers (pages 14787–14790)

      Tobias Groß and Prof. Dr. Peter Metz

      Article first published online: 2 OCT 2013 | DOI: 10.1002/chem.201302985

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      Au, yeah! Catalytic amounts of gold(III)chloride allow a mild and efficient oxidative domino cyclization/cycloaddition of enyne carbonyl compounds 1 and 4 to give the tetracycles 2 or 5, respectively, in the presence of pyridine N-oxide 3 (see scheme; DCE = 1,2-dichloroethane).

    6. Glucose Detection

      Ratiometric Fluorescent Probes for Hydrogen Peroxide from a Focused Library (pages 14791–14794)

      Sang Wook Lee, Prof. Hyun-Woo Rhee, Prof. Young-Tae Chang and Prof. Jong-In Hong

      Article first published online: 2 OCT 2013 | DOI: 10.1002/chem.201302523

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      Light shifting: Ratiometric fluorescent probes for hydrogen peroxide (H2O2) were developed through a focused library strategy. One of the probes in the library, showed a redshift of over 100 nm and an increase of over 30-fold in the emission intensity ratio (see scheme). This probe was utilized to detect H2O2 generated during glucose oxidation.

    7. Structure Elucidation

      Characterization of the Elusive Rhodizonate Ring-Contraction Decarbonylation C5O4(OH)CO2Me2− Intermediate to Croconate (pages 14795–14797)

      Dr. Feng Lu, Prof. Arnold L. Rheingold and Prof. Joel S. Miller

      Article first published online: 2 OCT 2013 | DOI: 10.1002/chem.201303190

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      Catch the intermediate! The oxidative ring contraction of aromatic rhodizonate, C6O62− (CO loss), forms the dinuclear [CoII(C5O4(OH)CO2Me)CoII]2+ core (see figure) possessing the planar, localized C5O4(OH)CO2Me2− five-membered ring that is the proposed intermediate in the oxidative ring contraction first reported in 1837.

    8. Water Chemistry

      Water Compatible Multicomponent Cascade Suzuki/Heck–Aldol, Suzuki–Aldol–Suzuki, and Aldol–Suzuki–Aldol Reactions: An Ecofriendly Paradigm for Multiple Carbon[BOND]Carbon Bond Formation in One Pot (pages 14798–14803)

      Rajesh Kumar, Richa, Nitin H. Andhare, Amit Shard and Dr. Arun K. Sinha

      Article first published online: 2 OCT 2013 | DOI: 10.1002/chem.201303069

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      Aryls in hot water: A versatile strategy has been devised for the synthesis of biologically active biaryl(hetero)chalcones from readily available precursors (see scheme). The method is step, pot, and carbon economic, ligand-free, devoid of toxic reagents/solvents, and has a wide substrate scope.

  6. Full Papers

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Concept
    6. Communications
    7. Full Papers
    1. Halogen Bonding

      Charge-Assisted Halogen Bonding: Donor–Acceptor Complexes with Variable Ionicity (pages 14804–14813)

      Dr. Julien Lieffrig, Dr. Olivier Jeannin, Arkadiusz Frąckowiak, Dr. Iwona Olejniczak, Roman Świetlik, Dr. Slimane Dahaoui, Dr. Emmanuel Aubert, Prof. Dr. Enrique Espinosa, Dr. Pascale Auban-Senzier and Dr. Marc Fourmigué

      Article first published online: 8 OCT 2013 | DOI: 10.1002/chem.201302507

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      Charge-assisted halogen bonding is apparent within a series of isostructural charge-transfer complexes with variable degrees of ionicity, (EDT-TTFI2)2(TCNQFn), n=0–2 (see graphic), together with temperature-driven neutral-ionic conversion with TCNQF (n=1).

    2. Solar Cells

      ZnSe Etching of Zn-Rich Cu2ZnSnSe4: An Oxidation Route for Improved Solar-Cell Efficiency (pages 14814–14822)

      Simón López-Marino, Yudania Sánchez, Dr. Marcel Placidi, Andrew Fairbrother, Moisés Espindola-Rodríguez, Xavier Fontané, Dr. Víctor Izquierdo-Roca, Dr. Juan López-García, Dr. Lorenzo Calvo-Barrio, Prof. Dr. Alejandro Pérez-Rodríguez and Dr. Edgardo Saucedo

      Article first published online: 10 OCT 2013 | DOI: 10.1002/chem.201302589

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      Se-rich kesterites are highly promising materials for low-cost thin-film photovoltaics and are usually grown under Zn-rich and Cu-poor conditions. Although these conditions lead to the presence of a ZnSe secondary phase, which is detrimental for device performance, the phase can be selectively and oxidatively removed by treating the material with KMnO4 in H2SO4 followed by aqueous Na2S (see graphic).

    3. Nanostructures

      Electrospun Hierarchical CaCo2O4 Nanofibers with Excellent Lithium Storage Properties (pages 14823–14830)

      Linlin Li, Dr. Shengjie Peng, Yanling Cheah, Yahwen Ko, Peifen Teh, Grace Wee, Dr. Chuiling Wong and Prof. Madhavi Srinivasan

      Article first published online: 8 OCT 2013 | DOI: 10.1002/chem.201302849

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      Home-spun fibers: Electrospun hierarchical CaCo2O4 nanofibes consisting of tightly stacked nanoplates exhibited a highly reversible capacity, superior cycling stability, and excellent rate capability, which can be attributed to the high specific surface area and the novel hierarchical 1D architecture.

    4. Heterogeneous Catalysis

      Synthesis of Catechol-, Pinacol-, and Neopentylglycolborane through the Heterogeneous Catalytic B[BOND]B Hydrogenolysis of Diboranes(4) (pages 14831–14835)

      Prof. Dr. Holger Braunschweig, Dr. Frank Guethlein, Lisa Mailänder and Prof. Dr. Todd B. Marder

      Article first published online: 20 SEP 2013 | DOI: 10.1002/chem.201302677

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      The fantastic (4): Catechol-, pinacol-, and neopentylglycolborane are useful reagents in organic synthesis. A new approach for the synthesis of these compounds is reported that proceeds through the hydrogenolysis of diboranes(4) under heterogeneous catalysis (see scheme).

    5. Regioselectivity

      Regiospecific Anomerisation of Acylated Glycosyl Azides and Benzoylated Disaccharides by Using TiCl4 (pages 14836–14851)

      Mark Farrell, Dr. Jian Zhou and Prof. Dr. Paul V. Murphy

      Article first published online: 20 SEP 2013 | DOI: 10.1002/chem.201302572

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      The place to be: Regiospecific site-directed anomerisation is demonstrated (see scheme). TiCl4 (2.5 equiv) was employed to induce anomerisation of 15 glycosyl azide and disaccharide substrates of low reactivity, and high yields (>75 %) and stereoselectivies (α/β>9:1) were achieved. The use of benzoylated saccharides was found to be important in disaccharide anomerisation.

    6. Cyclisation Reactions

      Synthesis of Densely Functionalised 5-Halogen-1,3-oxazin-2-ones by Halogen-Mediated Regioselective Cyclisation of N-Cbz-Protected Propargylic Amines: A Combined Experimental and Theoretical Study (pages 14852–14860)

      Alicia Monleón, Prof. Dr. Gonzalo Blay, Prof. Dr. Luis R. Domingo, Prof. Dr. M. Carmen Muñoz and Prof. Dr. José R. Pedro

      Article first published online: 18 SEP 2013 | DOI: 10.1002/chem.201302089

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      Regioselective­ O-halocyclisation: A halocyclisation reaction of chiral non-racemic N-carbobenzyloxy (Cbz)-protected propargylic amines by using I2, Br2 and Cl2 as electrophile sources (see scheme, Bn=benzyl) provides a very efficient synthesis of 5-halo-1,3-oxazin-2-ones. The reaction is totally regioselective, taking place through a 6-endo-dig process. The experimental results have been rationalised by theoretical studies at the B3LYP/6-311G* level.

    7. Asymmetric Synthesis

      Asymmetric Conjugate Addition of Malonate Esters to α,β-Unsaturated N-Sulfonyl Imines: An Expeditious Route to Chiral δ-Aminoesters and Piperidones (pages 14861–14866)

      Miguel Espinosa, Prof. Dr. Gonzalo Blay, Prof. Dr. Luz Cardona and Prof. Dr. José R. Pedro

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201302687

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      Expanding synthesis! Asymmetric conjugate addition of malonate esters to α,β-unsaturated N-sulfonyl imines is catalyzed by PyBOX/La(OTf)3 (see scheme) complexes in the presence of 4 Å MS. The reaction gives the corresponding E enamines bearing a stereogenic center at the allylic position with good yields and enantiomeric ratios up to 97:3. This reaction provides a synthetic entry to chiral δ-aminoesters and piperidones.

    8. Dendrimers

      Multivalency in the Gas Phase: H/D Exchange Reactions Unravel the Dynamic “Rock ’n’ Roll” Motion in Dendrimer–Dendrimer Complexes (pages 14867–14875)

      Zhenhui Qi, M. Sc. Christoph Schlaich and Prof. Christoph A. Schalley

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201301951

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      Dancing partners: Hydrogen/deuterium exchange experiments conducted on dendrimer–dendrimer complexes in the high vacuum of a mass spectrometer provide evidence for a very dynamic binding situation. Although the multivalent attachment increases the overall affinity, the microdynamics of individual site binding and dissociation remain fast (see figure).

    9. Lanthanide Clusters

      Anion-Templated Assembly and Magnetocaloric Properties of a Nanoscale {Gd38} Cage versus a {Gd48} Barrel (pages 14876–14885)

      Fu-Sheng Guo, Yan-Cong Chen, Ling-Ling Mao, Wei-Quan Lin, Ji-Dong Leng, Róbert Tarasenko, Prof. Dr. Martin Orendáč, Dr. Jan Prokleška, Prof. Dr. Vladimír Sechovský and Prof. Dr. Ming-Liang Tong

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201302093

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      The birdcage: Two novel nanoscale lanthanide hydroxide clusters, {Gd38} and {Gd48}, are reported. Moreover, the {Gd38} cage can be dynamically converted into the {Gd48} barrel upon Cl and NO3 stimulus (see figure). Both complexes display large magnetocaloric effects due to the dominant weak antiferromagnetic interactions, the high NGd/MW ratio, and the relatively compact crystal lattice.

    10. Metal–Organic Frameworks

      Expanded Organic Building Units for the Construction of Highly Porous Metal–Organic Frameworks (pages 14886–14894)

      Dr. Guo-Qiang Kong, Zhi-Da Han, Dr. Yabing He, Sha Ou, Dr. Wei Zhou, Prof. Dr. Taner Yildirim, Prof. Dr. Rajamani Krishna, Dr. Chao Zou, Prof. Dr. Banglin Chen and Prof. Dr. Chuan-De Wu

      Article first published online: 23 SEP 2013 | DOI: 10.1002/chem.201302515

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      Getting into the swing of things: Two new organic building units have been successfully developed to construct isoreticular porous metal–organic frameworks (see figure), the pores of which were systematically enlarged from 10.8 Å in HKUST-1 to 14.4 Å in ZJU-35 and 16.5 Å in ZJU-36. Compound ZJU-35 exhibits significant potential for high-pressure swing adsorption hydrogen purification.

    11. Substituent Effects

      Experimental and Computational Studies of Anti-Bredt Amidinium Salts (pages 14895–14901)

      Dr. David Martin, Dr. Nicolas Lassauque, Florian Steinmann, Gerald Manuel and Prof. Guy Bertrand

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201302474

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      Bent out of shape: Strained bicyclic N-bridgehead amidiniums can be significantly destabilized due to the decreased π donation to the formal carbocation center. The 1-aza-3-azonia[3.3.1]bicyclo-non-2-enes were found to meet the perfect balance: they can be isolated, but they still feature a nonclassical reactivity due to their distorted amino group (see scheme).

    12. Energetic Salts

      4-Nitro-3-(5-tetrazole)furoxan and Its Salts: Synthesis, Characterization, and Energetic Properties (pages 14902–14910)

      Lixuan Liang, Dr. Kai Wang, Chengming Bian, Liming Ling and Prof. Zhiming Zhou

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201301042

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      Salts go up with a bang! A series of energetic salts based on 4-nitro-3-(5-tetrazole)furoxan (see structure) has been synthesized. The densities of these salts have been found to range from 1.63 to 1.84 g cm−3. Their impact sensitivities have been determined by hammer tests, and ranged from 2 (very sensitive) to >40 J (insensitive). Theoretical performance calculations provided detonation pressures and velocities for the ionic compounds in the ranges 25.5–36.2 GPa and 7934–8919 m s−1, respectively, making them competitive energetic materials.

    13. Fluorescent Probes

      A Highly K+-Selective Phenylaza-[18]crown-6-Lariat-Ether-Based Fluoroionophore and Its Application in the Sensing of K+ Ions with an Optical Sensor Film and in Cells (pages 14911–14917)

      Dr. Sandra Ast, Dr. Thomas Schwarze, Holger Müller, Dr. Aleksey Sukhanov, Dr. Stefanie Michaelis, Prof. Dr. Joachim Wegener, Prof. Dr. Otto S. Wolfbeis, Prof. Dr. Thomas Körzdörfer, Dr. Axel Dürkop and Prof. Dr. Hans-Jürgen Holdt

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201302350

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      The crown jewels: A new phenylaza-[18]crown-6 lariat ether that contains a coumarin fluorophore (1) is an excellent fluorescent probe that shows high selectivity and sensitivity for K+ ions under simulated physiological conditions and in cells (see scheme). A fluorescent membrane sensor was prepared by incorporating probe 1 into a hydrogel, which showed a signal change of 7.8 % per 1 mM K+ within the range 1–10 mM K+.

    14. Biomimetic Synthesis

      Nanoscale Confinement Controls the Crystallization of Calcium Phosphate: Relevance to Bone Formation (pages 14918–14924)

      Bram Cantaert, Dr. Elia Beniash and Prof. Fiona C. Meldrum

      Article first published online: 20 SEP 2013 | DOI: 10.1002/chem.201302835

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      Bio-inspired crystallization: Investigation of calcium phosphate precipitation in confinement demonstrates multiple effects, including a stabilization of amorphous calcium phosphate and control over the orientation of hydroxyapatite crystals to a degree comparable to that seen in bone (see scheme). The results demonstrate that a structural match between hydroxyapatite and the collagen matrix is not a pre-requisite to orientation in bone.

    15. Zeolites

      Cyclodextrin-Modified Zeolites: Host–Guest Surface Chemistry for the Construction of Multifunctional Nanocontainers (pages 14925–14930)

      Dr. Anna Szarpak-Jankowska, Dr. Christine Burgess, Prof. Luisa De Cola and Prof. Dr. Jurriaan Huskens

      Article first published online: 13 SEP 2013 | DOI: 10.1002/chem.201302153

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      A “double host”: Functionalizing the surface of zeolite L with cyclodextrin allows the reversible capture of molecular cations in the zeolite channels, and the cyclodextrin cavities allow for selective anchoring of guest molecules or proteins through supramolecular self-assembly (see figure). Such a system holds promise for the construction of multifunctional hybrid nanocontainers with potential applications in targeted drug delivery.

    16. Fullerene Cycloaddition

      A Complete Guide on the Influence of Metal Clusters in the Diels–Alder Regioselectivity of Ih-C80 Endohedral Metallofullerenes (pages 14931–14940)

      Marc Garcia-Borràs, Dr. Sílvia Osuna, Dr. Josep M. Luis, Prof. Marcel Swart and Prof. Miquel Solà

      Article first published online: 13 SEP 2013 | DOI: 10.1002/chem.201302202

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      Predicting regioselectivity: To improve the understanding of endohedral metallofullerene (EMF) reactivity, the Diels–Alder cycloaddition reaction between butadiene and practically all X@Ih-C80 EMFs synthesized to date has been studied (see figure), looking at both the thermodynamic and kinetic regioselectivity, and taking into account the free rotation of the metallic cluster inside the fullerene.

    17. Porphyrin Networks

      Exploring Supramolecular Self-Assembly of Tetraarylporphyrins by Halogen Bonding: Crystal Engineering with Diversely Functionalized Six-Coordinate Tin(L)2–Porphyrin Tectons (pages 14941–14949)

      Hatem M. Titi, Dr. Ranjan Patra and Prof. Israel Goldberg

      Article first published online: 13 SEP 2013 | DOI: 10.1002/chem.201301857

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      Porphyrins in tandem: Porphyrin-based network materials can been supramolecularly organized into one-dimensional and two-dimensional structures by means of cooperative directional halogen bonding (see figure).

    18. Hydrogels

      An Amino-Acid-Based Self-Healing Hydrogel: Modulation of the Self-Healing Properties by Incorporating Carbon-Based Nanomaterials (pages 14950–14957)

      Subhasish Roy, Abhishek Baral and Prof. Arindam Banerjee

      Article first published online: 13 SEP 2013 | DOI: 10.1002/chem.201301655

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      Physician, heal thyself: An amino-acid-based (11-(4-(pyrene-1-yl)butanamido)undecanoic acid) self-repairing hydrogel has been discovered under basic pH conditions. Interestingly, the thixotropy, self-healing, and stiffness of the gel were successfully tuned by incorporating carbon-based nanomaterials, such as reduced graphene oxide (RGO) and/or pristine single-walled carbon nanotubes (Pr-SWCNTs).

    19. Plasmon Chemistry

      Plasmonic Scissors for Molecular Design (pages 14958–14962)

      Prof. Mengtao Sun, Dr. Zhenglong Zhang , Prof. Zee Hwan Kim, Prof. Hairong Zheng and Prof. Hongxing Xu

      Article first published online: 13 SEP 2013 | DOI: 10.1002/chem.201302610

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      Cut to order: The N[DOUBLE BOND]N bond of 4,4′-dimercaptoazobenzene was selectively dissociated by plasmonic scissors in a high-vacuum tip-enhanced Raman spectroscopy setup. p-Aminothiophenol (PATP) and 4-nitrobenzenethiol (4NBT) were produced from the radical fragments by attachment of hydrogen and oxygen ions under acidic and alkaline conditions, respectively (see figure). These findings suggest new ways to acquire insight into functioning molecular catalysts and their application in chemical catalysis and molecular dissociation.

    20. Helical Structures

      Synthesis of an Orthogonal Topological Analogue of Helicene (pages 14963–14969)

      Torbjörn Wixe, Dr. Carl-Johan Wallentin, Dr. Magnus T. Johnson, Dr. Peter Fristrup, Prof. Sven Lidin and Prof. Kenneth Wärnmark

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201302278

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      Parallel universe! An orthogonal topological analogue of helicene (see figure) was synthesized from optically pure bicyclo[3.3.1]nonane-2,6-dione. This is the first example of a helical, covalent, tubular molecule with its aromatic surface parallel to its axis of propagation.

    21. Bioluminescence

      Development of Luminescent Coelenterazine Derivatives Activatable by β-Galactosidase for Monitoring Dual Gene Expression (pages 14970–14976)

      Eric Lindberg, Dr. Shin Mizukami, Dr. Keiji Ibata, Dr. Atsushi Miyawaki and Prof. Kazuya Kikuchi

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201302002

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      Sweet flash: A caged coelenterate luciferin derivative to detect β-galactosidase activity through bioluminescence was developed. The probe is composed of coelenterazine, a self-immolative nitrobenzyl linker, and a β-galactose moiety (see figure). The derivative showed high stability, fast cleavage kinetics, and allowed the measurement of β-galactosidase (β-Gal) activity in living cells with a new mutant Gaussia luciferase (GLuc).

    22. Enzyme Sensors

      Bi-Enzyme Sensor for Phenolic Compounds with Fluorescent Read-Out (pages 14977–14982)

      Dr. Maria Strianese, Dr. Gerhild Zauner, Dr. Leandro C Tabares, Dr. Armand W. J. W. Tepper, Dr. Franco De Martino, Prof. Claudio Pellecchia, Prof. Thijs J. Aartsma and Prof. Gerard W. Canters

      Article first published online: 20 SEP 2013 | DOI: 10.1002/chem.201301876

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      Highly amplified detection of phenols: A new biosensor for the detection of trace amounts of phenols in aqueous solution that is based on the use of fluorescently labeled tyrosinase (Ty) and soluble glucose dehydrogenase (s-GDH) is presented (see figure; TBC=4-tert-butyl catechol). The detection is based on a Förster resonant energy transfer mechanism. The only instrumentation required is a simple fluorimeter.

    23. Flash Pyrolysis

      New Reactions of N-tert-Butylimines; Formation of N-Heterocycles by Methyl Radical Elimination on Flash Vacuum Thermolysis of N-Benzylidene- and N-(2-Pyridylmethylidene)-tert-butylamines (pages 14983–14988)

      Thien Y Vu, Prof. Anna Chrostowska, Prof. Thi Kieu Xuan Huynh, Prof. Saïd Khayar, Prof. Alain Dargelos, Katarzyna Justyna, Dr. Beata Pasternak, Prof. Stanisław Leśniak and Prof. Curt Wentrup

      Article first published online: 20 SEP 2013 | DOI: 10.1002/chem.201301663

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      Hot rearrangement: Flash vacuum thermolysis (FVT) of N-benzylidene- and N-(2-pyridylmethylidene)-tert-butylamines resulted in unexpected rearrangements (see scheme). At 800 °C, 1 gave 1,2-dimethylindole (2) and 3-methylisoquinoline (3) as the main products, whereas 4 afforded 3-methylimidazo[1,5-a]pyridine (5) in high yield. A combination of FVT with UV-photoelectron spectroscopy was used to monitor the thermolysis products in situ.

    24. NMR Spectroscopy

      Conformational Analysis of the Anti-obesity Drug Lorcaserin in Water: How To Take Advantage of Long-Range Residual Dipolar Couplings (pages 14989–14997)

      Dr. Pablo Trigo-Mouriño, Dr. M. Carmen de la Fuente, Dr. Roberto R. Gil, Dr. Víctor M. Sánchez-Pedregal and Dr. Armando Navarro-Vázquez

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201202509

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      NMR-based conformational analysis of flexible small molecules in solution is improved by the incorporation of long-range C[BOND]H residual dipolar couplings (RDCs; 2DCH) to one-bond RDCs (1DCH; see picture). Applying this to the anti-obesity drug, lorcaserin, shows that it exists in solution as two crown-chair forms in equilibrium.

    25. Crystal Engineering

      Ranking Relative Hydrogen-Bond Strengths in Hydroxybenzoic Acids for Crystal-Engineering Purposes (pages 14998–15003)

      Dr. Christer B. Aakeröy, Kanishka Epa, Dr. Safiyyah Forbes, Dr. Nathan Schultheiss and Dr. John Desper

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201301402

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      Intermolecular interactions: A ranking based on electrostatic charge and tested against structural data indicates that the [BOND]OH moiety is a better hydrogen-bond donor than the [BOND]COOH site in hydroxybenzoic acids (see scheme).

    26. Biaryl Coupling

      Single-Electron-Transfer (SET)-Induced Oxidative Biaryl Coupling by Polyalkoxybenzene-Derived Diaryliodonium(III) Salts (pages 15004–15011)

      Nobutaka Yamaoka, Kohei Sumida, Itsuki Itani, Hiroko Kubo, Yusuke Ohnishi, Sho Sekiguchi, Dr. Toshifumi Dohi and Prof. Dr. Yasuyuki Kita

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201301148

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      Coupling in the pair: Metal-free oxidative C[BOND]C coupling to yield electron-rich biaryls has been achieved by using polyalkoxybenzene-derived diaryliodonium(III) salts as both the oxidant and aryl source. These salts can induce single-electron-transfer (SET) oxidation towards electron-rich aromatic compounds and subsequently transfer the polyalkoxyphenyl group into in situ generated aromatic radical cations to produce biaryl products (see scheme).

    27. Aliphatic Alkenes

      Fe-Catalyzed One-Pot Oxidative Cleavage of Unsaturated Fatty Acids into Aldehydes with Hydrogen Peroxide and Sodium Periodate (pages 15012–15018)

      Peter Spannring, Vital Yazerski, Dr. Pieter C. A. Bruijnincx, Prof. Dr. Bert M. Weckhuysen and Prof. Dr. Robertus J. M. Klein Gebbink

      Article first published online: 18 SEP 2013 | DOI: 10.1002/chem.201301371

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      One pot, many products: A one-pot protocol for the conversion of aliphatic alkenes into aldehydes is reported. The protocol uses a nonheme iron catalyst based on a nonresolved mixture of bis(2-picolyl)bipyrrolidine ligands in the initial epoxidation step and a combination of H2O2 and NaIO4 as oxidant (see scheme). A variety of aliphatic alkenes can be converted into aldehydes within 4–20 h in good yields.

    28. Click Chemistry

      From Nongelating to Gelating: Synthesis and Structural Self-Assembling Property Relationships of a Homologous Series of Oligo(amide–triazole)s (pages 15019–15025)

      Dr. Juntao Zhang, Prof. Dr. Hak-Fun Chow, Prof. Dr. Man-Chor Chan, Gary Ka-Wai Chow and Prof. Dr. Dietmar Kuck

      Article first published online: 11 SEP 2013 | DOI: 10.1002/chem.201300682

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      All's gel that ends gel: The thermoreversible gelation strength of a series of oligo(amide–triazole)s was found to increase with increasing number of primary amide hydrogen-bonding units inside the oligomer (see figure). The triazole C[BOND]H bonds were also found to participate in the hydrogen-bond-mediated self-assembly process.

    29. Mesocrystals

      Lyotropic Liquid Crystal to Soft Mesocrystal Transformation in Hydrated Salt–Surfactant Mixtures (pages 15026–15035)

      Dr. Cemal Albayrak, Gözde Barım and Prof. Ömer Dag

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201301662

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      A soft touch: A new type of very unusual mesocrystal was discovered. Some hydrated alkali (such as LiI) and alkaline-earth (such as CaCl2 and MgCl2) metal salts and 10-lauryl ether (C12H25(OCH2CH2)10OH) form lyotropic liquid-crystalline mesophases that undergo transformation to new soft mesocrystals (see figure).

    30. Spin Crossover

      Tunable Spin-Crossover Behavior of the Hofmann-like Network {Fe(bpac)[Pt(CN)4]} through Host–Guest Chemistry (pages 15036–15043)

      Dr. Carlos Bartual-Murgui, Dr. Amal Akou, Dr. Helena J. Shepherd, Dr. Gábor Molnár, Prof. Dr. J. Antonio Real, Dr. Lionel Salmon and Dr. Azzedine Bousseksou

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201300227

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      Host in a spin: Mono- and polyhalobenzene guest molecules affect the spin-crossover (SCO) properties of the three-dimensional porous coordination polymer {Fe(bpac)[Pt(CN)4]} (bpac = bis(4-pyridyl)acetylene). The crystal structure of {Fe(bpac)[Pt(CN)4]}TClBz (TClBz = 1,2,4-trichlorobenzene, see figure) shows π⋅⋅⋅π stacking interactions with the host framework. The SCO behavior is influenced by both the nature and quantity of the guest molecule.

    31. Organic Electronics

      Phenylethenyl-Substituted Triphenylamines: Efficient, Easily Obtainable, and Inexpensive Hole-Transporting Materials (pages 15044–15056)

      Dr. Tadas Malinauskas, Dr. Maryte Daskeviciene, Dr. Giedre Bubniene, Ieva Petrikyte, Steponas Raisys, Dr. Karolis Kazlauskas, Dr. Valentas Gaidelis, Dr. Vygintas Jankauskas, Dr. Robertas Maldzius, Prof. Saulius Jursenas and Prof. Vytautas Getautis

      Article first published online: 17 SEP 2013 | DOI: 10.1002/chem.201204064

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      One small step: Star-shaped charge-transporting materials with a triphenylamine core and various phenylethenyl side arms can be obtained in one step from commercially available, inexpensive starting materials. The dense side-arm network formed in the solid state enables very good charge drift mobility ( μh up to 0.017 cm2 V −1 s−1; see scheme).

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