ChemPhysChem

Cover image for Vol. 15 Issue 8

June 6, 2014

Volume 15, Issue 8

Pages 1521–1707

  1. Cover Pictures

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Minireviews
    6. Communications
    7. Articles
    1. You have free access to this content
      Cover Picture: Porosity-Controlled Eggshell Membrane as 3D SERS-Active Substrate (ChemPhysChem 8/2014) (page 1521)

      Pei-Ying Lin, Chiung-Wen Hsieh, Pei-Chuan Tsai and Prof. Shuchen Hsieh

      Version of Record online: 30 MAY 2014 | DOI: 10.1002/cphc.201490035

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      S. Hsieh et al. present on p. 1577 a SERS platform comprised of a 3D porous eggshell membrane (ESM) scaffold decorated with Ag nanoparticles. ESM-based SERS substrates exhibit a strong signal enhancement, biocompatibility, high pore density and good reproducibility.

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      Inside Cover: Free Carrier Generation in Organic Photovoltaic Bulk Heterojunctions of Conjugated Polymers with Molecular Acceptors: Planar versus Spherical Acceptors (ChemPhysChem 8/2014) (page 1522)

      Dr. Alexandre M. Nardes, Dr. Andrew J. Ferguson, Dr. Pascal Wolfer, Dr. Kurt Gui, Dr. Paul L. Burn, Dr. Paul Meredith and Dr. Nikos Kopidakis

      Version of Record online: 30 MAY 2014 | DOI: 10.1002/cphc.201490036

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      On p. 1539 N. Kopidakis et al. present a comparative study of the photophysical performance of a prototypical fullerene derivative with a planar small molecule acceptor in an organic photovoltaic device. The shapes of the molecules determine the performance of the device in more than one way.

  2. Graphical Abstract

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Minireviews
    6. Communications
    7. Articles
  3. News

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Minireviews
    6. Communications
    7. Articles
  4. Minireviews

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Minireviews
    6. Communications
    7. Articles
    1. Free Carrier Generation in Organic Photovoltaic Bulk Heterojunctions of Conjugated Polymers with Molecular Acceptors: Planar versus Spherical Acceptors (pages 1539–1549)

      Dr. Alexandre M. Nardes, Dr. Andrew J. Ferguson, Dr. Pascal Wolfer, Dr. Kurt Gui, Dr. Paul L. Burn, Dr. Paul Meredith and Dr. Nikos Kopidakis

      Version of Record online: 5 MAR 2014 | DOI: 10.1002/cphc.201301022

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      A square peg into a round hole? Contactless photoconductivity studies of poly(3-n-hexylthiophene):acceptor bulk heterojunctions indicate that a spherical acceptor shuttles electrons out of the mixed phase. In contrast, a planar acceptor forms a glassy mixed phase, characterized by strong interactions between the donor and acceptor, which results in poor electronic coupling between acceptor molecules, hindered electron transport, and enhanced carrier recombination.

    2. Designing Fractal Nanostructured Biointerfaces for Biomedical Applications (pages 1550–1561)

      Dr. Pengchao Zhang and Prof. Shutao Wang

      Version of Record online: 18 MAR 2014 | DOI: 10.1002/cphc.201301230

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      Facing forward: Fractal structures offer a unique “fractal contact mode” that guarantees the efficient working of organisms with an optimized style. Fractal nanostructured biointerfaces show great potential for the ultrasensitive detection of various disease-relevant biomarkers, such as microRNA, cancer antigen 125, and breast cancer cells, from unpurified cell lysates and the blood of patients.

  5. Communications

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Minireviews
    6. Communications
    7. Articles
    1. Visualization of the Heterogeneity of Cerium Oxidation States in Single Pt/Ce2Zr2Ox Catalyst Particles by Nano-XAFS (pages 1563–1568)

      Dr. Nozomu Ishiguro, Prof. Dr. Tomoya Uruga, Dr. Oki Sekizawa, Dr. Takuya Tsuji, Dr. Motohiro Suzuki, Dr. Naomi Kawamura, Dr. Masaichiro Mizumaki, Dr. Kiyofumi Nitta, Prof. Dr. Toshihiko Yokoyama and Prof. Dr. Mizuki Tada

      Version of Record online: 11 MAR 2014 | DOI: 10.1002/cphc.201400090

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      State heterogeneity: The cerium oxidation states in single catalyst particles of Pt/Ce2Zr2Ox (x=7 to 8) are investigated by spatially resolved nano-XAFS using an X-ray nanobeam. Differences in the distribution of Ce oxidation states between Pt/Ce2Zr2Ox single particles of different oxygen compositions x are visualized in the obtained 2D XRF mapping images and the Ce LIII-edge nano-XANES spectra.

    2. Effects of Adsorbate Coverage and Bond-Length Disorder on the d-Band Center of Carbon-Supported Pt Catalysts (pages 1569–1572)

      Dr. Matthew W. Small, Dr. Joshua J. Kas, Dr. Kristina O. Kvashnina, Prof. Dr. John J. Rehr, Prof. Dr. Ralph G. Nuzzo, Prof. Dr. Moniek Tromp and Prof. Dr. Anatoly I. Frenkel

      Version of Record online: 13 MAR 2014 | DOI: 10.1002/cphc.201400055

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      Don't let disorder bother you: Using resonant inelastic X-ray scattering (RIXS) measurements the changes in the d-band center of carbon-supported Pt nanocatalysts are imaged in response to variable temperatures and gas atmospheres. Theoretical analysis of RIXS data reveals that the d-band-center shift toward the Fermi level at elevated temperatures is dominated by the decrease in adsorbate coverage, whereas the increase of bond-length disorder plays no significant role.

    3. Label-Free Biosensing over a Wide Concentration Range with Photonic Force Microscopy (pages 1573–1576)

      Seungjin Heo, Prof. Kipom Kim and Prof. Yong-Hoon Cho

      Version of Record online: 1 APR 2014 | DOI: 10.1002/cphc.201301107

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      Don′t label me: A label-free biosensor that uses photonic force microscopy, which measures molecular interactions between biomolecules on the surface of a probe bead and substrate, is presented. The biosensor exhibits both high selectivity and high sensitivity.

    4. Porosity-Controlled Eggshell Membrane as 3D SERS-Active Substrate (pages 1577–1580)

      Pei-Ying Lin, Chiung-Wen Hsieh, Pei-Chuan Tsai and Prof. Shuchen Hsieh

      Version of Record online: 3 MAR 2014 | DOI: 10.1002/cphc.201301222

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      Fuzzy surface: Porous eggshell membranes (ESMs) decorated with Ag nanoparticles are used as three-dimensional surface-enhanced Raman scattering (SERS)-active substrates for 4-aminothiophenol (ATP) and 4-mercaptobenzoic acid (MBA) detection. Pre-treatment of the ESM by H2O2 leads to stronger SERS enhancement, which is attributed to the increased ESM fiber crossing density and hot spot probability (see picture).

    5. Intrinsic Flexibility of the Zeolitic Imidazolate Framework ZIF-7 Unveiled by CO2 Adsorption and Hg Intrusion (pages 1581–1586)

      Dr. Marc Pera-Titus

      Version of Record online: 14 MAY 2014 | DOI: 10.1002/cphc.201400084

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      Opening the gate: By a convenient thermodynamic treatment of the CO2 adsorption/desorption and Hg intrusion curves, a major entropic contribution to the elastic energy stored by ZIF-7 during the np[RIGHTWARDS ARROW]lp transition is unveiled.

  6. Articles

    1. Top of page
    2. Cover Pictures
    3. Graphical Abstract
    4. News
    5. Minireviews
    6. Communications
    7. Articles
    1. Sample Preparation of Energy Materials for X-ray Nanotomography with Micromanipulation (pages 1587–1591)

      Dr. Yu-chen Karen Chen-Wiegart, Dr. Fernando E. Camino and Dr. Jun Wang

      Version of Record online: 25 MAR 2014 | DOI: 10.1002/cphc.201400023

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      It′s all in the prep: Novel sample preparation for X-ray nanotomography by using focused-ion-beam (FIB) and micromanipulation ensures high-quality data. The proposed procedure resolves the issues that cause the view of the sample base to be blocked after FIB milling and during the lift-out process. This method enables the broad application of X-ray nanotomography in microstructure studies.

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      Thermal Expansion, Anharmonicity and Temperature-Dependent Raman Spectra of Single- and Few-Layer MoSe2 and WSe2 (pages 1592–1598)

      Dr. Dattatray J. Late, Sharmila N. Shirodkar, Prof. Umesh V. Waghmare, Prof. Vinayak P. Dravid and Prof. C. N. R. Rao

      Version of Record online: 1 APR 2014 | DOI: 10.1002/cphc.201400020

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      Special effects in 2D: The temperature-dependent Raman spectra of single- and few-layer MoSe2 and WSe2 in the 77–700 K range are reported. Linear variation is observed in the peak positions and widths of the bands arising from contributions of anharmonicity and thermal expansion.

    3. Electronic Structure of N2P2 Four-Membered Rings (pages 1599–1603)

      Dr. Daniel Escudero, Prof. Antonio Frontera and Prof. Dr. Rainer Streubel

      Version of Record online: 5 MAR 2014 | DOI: 10.1002/cphc.201301233

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      Ab Fab: The biradicaloid character of the ground-state structures of N2P2 rings is analyzed by using the high-level ab initio CASPT2/CASSCF multiconfigurational method. To obtain accurate descriptors we combine the singlet–triplet energy gaps with the relative values of the occupation numbers for bonding and antibonding orbitals associated with the radical sides. A percentage biradicaloid character is provided.

    4. Mechanism of Dissolution of a Lithium Salt in an Electrolytic Solvent in a Lithium Ion Secondary Battery: A Direct Ab Initio Molecular Dynamics (AIMD) Study (pages 1604–1610)

      Dr. Hiroto Tachikawa

      Version of Record online: 11 MAR 2014 | DOI: 10.1002/cphc.201301151

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      Real-time solvation of Li+: The mechanism of dissolution of the Li+ ion in an electrolytic solvent is investigated by the direct ab initio molecular dynamics method. Lithium fluoroborate (Li+BF4) and ethylene carbonate are examined as the origin of the Li+ ion and the solvent molecule, respectively.

    5. Band-Structure Engineering of ZnO by Anion–Cation Co-Doping for Enhanced Photo-Electrochemical Activity (pages 1611–1618)

      Jing Pan, Dr. Shudong Wang, Dr. Qian Chen, Prof. Jingguo Hu and Prof. Jinlan Wang

      Version of Record online: 6 MAR 2014 | DOI: 10.1002/cphc.201301059

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      Shred the gap: To achieve a highly efficient ZnO-based photocatalyst for hydrogen production by photo-electrochemical water splitting, ZnO is co-doped with compensated and noncompensated n–p pairs. This results in narrowed band-gaps, reduced electron–hole recombination centers, suitable band-edge positions, enhanced optical absorption, and good stability, by comparison with undoped ZnO.

    6. Large Magnetocaloric Effect, Moment, and Coercivity Enhancement after Coating Ni Nanoparticles with Ag (pages 1619–1623)

      Dr. Sanyadanam Srinath, Dr. Pankaj Poddar, Raja Das, Dr. Deepti Sidhaye, Dr. Bhagavatula Lakshmi Vara Prasad, Dr. James Gass and Prof. Hariharan Srikanth

      Version of Record online: 11 MAR 2014 | DOI: 10.1002/cphc.201300886

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      What a difference a coat makes: A large magnetocaloric effect is observed in monodisperse Ni and NicoreAgshell nanoparticles in the superparamagnetic region. The organically passivated Ni nanospheres show a large magnetic entropy change of 0.9 J kg−1 K for a 3 T magnetic field change. This large enhancement is attributed to the enhanced inter-particle interaction mediated by the metallic shell, and modification of the surface spin structure.

    7. ZnGa2O4 Nanorod Arrays Decorated with Ag Nanoparticles as Surface-Enhanced Raman-Scattering Substrates for Melamine Detection (pages 1624–1631)

      Dr. Limiao Chen, Dan Jiang, Prof. Xiaohe Liu and Prof. Guanzhou Qiu

      Version of Record online: 26 MAR 2014 | DOI: 10.1002/cphc.201400050

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      Array of sunshine: ZnGa2O4 nanorod arrays grown on Si are used as templates to fabricate surface-enhanced Raman spectroscopy (SERS) substrates by deposition of Ag nanoparticles onto the nanorods. The coverage of the nanoparticles on the nanorods is easily controlled by varying the amount of AgNO3. SERS measurements show that the number density of the Ag nanoparticles on the nanorods has a great effect on SERS activity.

    8. Effect of Nanoscale Confinement on Freezing of Modified Water at Room Temperature and Ambient Pressure (pages 1632–1642)

      Dr. Sanket Deshmukh, Dr. Ganesh Kamath and Dr. Subramanian K. R. S. Sankaranarayanan

      Version of Record online: 8 APR 2014 | DOI: 10.1002/cphc.201400016

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      Creating ice at room temperature: At room temperature, ice nucleation is a very rare event and extremely high pressures in the GPa–TPa range are required to freeze water. Computer experiments are performed to artificially alter the balance between electrostatic and dispersion interactions between water molecules, and nucleation and growth of ice at room temperature in a nanoconfined environment is demonstrated.

    9. Excited-State Intramolecular Proton Transfer: Photoswitching in Salicylidene Methylamine Derivatives (pages 1643–1652)

      Joanna Jankowska, Dr. Michał F. Rode, Prof. Joanna Sadlej and Prof. Andrzej L. Sobolewski

      Version of Record online: 29 APR 2014 | DOI: 10.1002/cphc.201301205

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      Flick that switch: A theoretical attempt to control the photophysical properties of salicylidene methylamine-based molecular systems through a chemical substitution effect is reported (see figure; CI=conical intersection, PT=proton transfer). An electron-density push-and-pull effect is shown to be a promising tool for efficient photoswitching control.

    10. Intramolecular Interactions of Trityl Groups (pages 1653–1659)

      Dr. Jacek Ściebura, Dr. Agnieszka Janiak, Agata Stasiowska, Dr. Jakub Grajewski, Dr. Krystyna Gawrońska, Prof. Dr. Urszula Rychlewska and Prof. Dr. Jacek Gawroński

      Version of Record online: 1 APR 2014 | DOI: 10.1002/cphc.201301204

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      Chirality at work: Interactions with proximal groups cause the C3 symmetrical trityl group to adopt a structure of nonregular helicity. This conformation can be detected by X-ray diffraction analysis, calculation of molecular structures, and comparison of experimental and calculated electronic circular dichroism spectra if the molecular framework is chiral, as in derivatives of trans-1,2-diols and diamines.

    11. Coronene Encapsulation in Single-Walled Carbon Nanotubes: Stacked Columns, Peapods, and Nanoribbons (pages 1660–1665)

      Dr. Ilya V. Anoshkin, Dr. Alexandr V. Talyzin, Prof. Albert G. Nasibulin , Dr. Arkady V. Krasheninnikov, Hua Jiang, Prof. Risto M. Nieminen and Prof. Esko I. Kauppinen

      Version of Record online: 11 APR 2014 | DOI: 10.1002/cphc.201301200

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      Argon or vacuum? Encapsulation of coronene into single-walled carbon nanotubes (SWNTs) under an atmosphere of argon results in the preferential formation of graphene nanoribbons. Vacuum conditions favor encapsulation of monomer (coronene) and dimer (dicoronylene) molecules in a variety of geometries, including stacking columns and peapods. The morphology of the encapsulated products depends on the diameter of the SWNTs.

    12. Low Effective Activation Energies for Oxygen Release from Metal Oxides: Evidence for Mass-Transfer Limits at High Heating Rates (pages 1666–1672)

      Guoqiang Jian, Dr. Lei Zhou, Dr. Nicholas W. Piekiel and Dr. Michael R. Zachariah

      Version of Record online: 11 MAR 2014 | DOI: 10.1002/cphc.201301148

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      Oxygen release from metal oxides: The thermal decomposition of nanosized metal oxides are evaluated under rapid heating (∼105 K s−1) with time-resolved mass spectrometry. It is found that the effective activation energies obtained using the Flynn–Wall–Ozawa isoconversional method are much lower than the activation energies under low heating rates, indicating that oxygen transport might be rate-determining at high heating rates.

    13. Theoretical Design of Multi-Nitroxyl Organocatalysts with Enhanced Reactivity for Aerobic Oxidation (pages 1673–1680)

      Dr. Kexian Chen, Dr. Lu Jia, Prof. Dr. Congmin Wang, Prof. Dr. Jia Yao, Prof. Dr. Zhirong Chen and Prof. Dr. Haoran Li

      Version of Record online: 11 MAR 2014 | DOI: 10.1002/cphc.201301141

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      The future of organocatalysts: A theoretical design strategy for multi-nitroxyl organocatalysts for aerobic oxidation is proposed. Their reactivity can be enhanced by increasing the hydroxyimide groups or doped N atoms or ionic-pair groups on the aromatic ring (see picture). Appropriate enlargement of the conjugated aromatic system does not change the reactivity. These results may serve as a route towards conjugated heterogeneous species with multiple hydroxyimide groups.

    14. Probing Mass Transfer in Mesoporous Faujasite-Type Zeolite Nanosheet Assemblies (pages 1681–1686)

      Dirk Mehlhorn, Alexandra Inayat, Prof. Dr. Wilhelm Schwieger, Dr. habil. Rustem Valiullin and Prof. Dr. Jörg Kärger

      Version of Record online: 20 MAR 2014 | DOI: 10.1002/cphc.201301133

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      Diffusion enhancement in pore-space hierarchies: Pulsed field gradient NMR spectroscopy is applied for probing mass transfer in zeolite NaX samples, which are formed as house-of-cards-like assemblies of mesoporous nanosheets. The intraparticle diffusivity of cyclohexane at room temperature is found to exceed that in the purely microporous sample by one order of magnitude, indicating greater enhancement with increasing temperature.

    15. Ultrafast Two-Dimensional NMR Relaxometry for Investigating Molecular Processes in Real Time (pages 1687–1692)

      Dr. Susanna Ahola and Dr. Ville-Veikko Telkki

      Version of Record online: 13 MAR 2014 | DOI: 10.1002/cphc.201301117

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      2D­ T1-T2 correlation map with a single scan! Multidimensional NMR relaxometry methods provide much more detailed information about the dynamics and structure of substances than their 1D counterpart. However, the long experimental time (from minutes to hours) of the methods restricts their use in the investigations of fast processes in real-time. An efficient strategy for a single-scan measurement of a 2D T1-T2 map is presented.

    16. A Novel pH/Light-Triggered Surface for DNA Adsorption and Release (pages 1693–1699)

      Prof. Gökçen Birlik Demirel

      Version of Record online: 19 MAR 2014 | DOI: 10.1002/cphc.201301110

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      Controllable DNA adsorption/release: New dual pH/light-triggered self-assembled monolayers (SAMs) are developed and show the possibility of controllable adsorption/release cycles for Cy3-labeled single strand DNA (Cy3-ssDNA) for biological applications.

    17. Framework Stability and Brønsted Acidity of Isomorphously Substituted Interlayer-Expanded Zeolite COE-4: A Density Functional Theory Study (pages 1700–1707)

      Haichao Li, Prof. Dr. Danhong Zhou, Dr. Dongxu Tian, Prof. Dr. Chuan Shi, Dr. Ulrich Müller, Dr. Mathias Feyen, Dr. Bilge Yilmaz, Prof. Dr. Hermann Gies, Prof. Dr. Feng-Shou Xiao, Prof. Dr. Dirk De Vos, Prof. Dr. Toshiyuki Yokoi, Prof. Dr. Takashi Tatsumi, Prof. Dr. Xinhe Bao and Prof. Dr. Weiping Zhang

      Version of Record online: 18 MAR 2014 | DOI: 10.1002/cphc.201301033

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      Calculating exchange: Density functional theory is employed to survey the differences in the structure, stability, and Brønsted-acidic properties at the linker-T active site, in which the tetrahedral silicon is isomorphously substituted by a Fe, B, Ga, or Al atom in the interlayer-expanded zeolite, COE-4. Substitution energy and geometric parameters of T-COE-4 zeolites are discussed in detail, and their relative acid strengths are predicted.

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