ChemPhysChem

Cover image for Vol. 8 Issue 3

February 19, 2007

Volume 8, Issue 3

Pages 333–490

  1. Cover Picture

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
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    1. Cover Picture: Two-Focus Fluorescence Correlation Spectroscopy: A New Tool for Accurate and Absolute Diffusion Measurements (ChemPhysChem 3/2007) (page 333)

      Thomas Dertinger, Victor Pacheco, Iris von der Hocht, Rudolf Hartmann, Ingo Gregor and Jörg Enderlein

      Article first published online: 8 FEB 2007 | DOI: 10.1002/cphc.200790004

      The cover picture shows the two focal regions of a two-focus fluorescence correlation spectroscopy set-up with molecules diffusing through these regions. The depicted curves are the fluorescence autocorrelation curves for the first and the second focus, respectively, as well as the fluorescence cross-correlation between both foci. In their Article on page 433 Dertinger et al. introduce an external ruler into a fluorescence correlation measurement by having two focal regions with a fixed and well-defined distance. This allows for absolute and precise determination of molecular diffusion.

  2. Graphical Abstract

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    1. Graphical Abstract: ChemPhysChem 3/2007 (pages 335–341)

      Article first published online: 8 FEB 2007 | DOI: 10.1002/cphc.200790005

  3. Minireview

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    1. Kinetics in Cold Laval Nozzle Expansions: From Atmospheric Chemistry to Oxidation of Biomolecules in the Gas Phase (pages 343–356)

      Björn Hansmann and Bernd Abel

      Article first published online: 8 FEB 2007 | DOI: 10.1002/cphc.200600646

      Thumbnail image of graphical abstract

      Probing molecular dynamics at low temperatures: New developments and recent applications of pulsed and miniaturised Laval nozzle technology allowing many gas-phase molecular processes to be studied at very low temperatures (see picture) are highlighted in this Minireview.

  4. Articles

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    1. In Situ SAXS/WAXS of Zeolite Microwave Synthesis: NaY, NaA, and Beta Zeolites (pages 357–369)

      Bernard Panzarella, Geoffrey Tompsett, William C. Conner and Keith Jones

      Article first published online: 25 JAN 2007 | DOI: 10.1002/cphc.200600496

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      When the heat is on: Microwaves can increase the rate of zeolite synthesis or change the selectivity of the reaction. The formation of aluminosilicate zeolites under microwave heating is explored in real time by in situ X-ray scattering. The picture shows the wide-angle X-ray scattering spectra of NaY zeolite during crystallization.

    2. Physico-Chemical Characterization of Nanofiltration Membranes (pages 370–379)

      Katleen Boussu, Jérémie De Baerdemaeker, Charles Dauwe, Marc Weber, Kelvin G. Lynn, Diederik Depla, Steliana Aldea, Ivo F. J. Vankelecom, Carlo Vandecasteele and Bart Van der Bruggen

      Article first published online: 17 JAN 2007 | DOI: 10.1002/cphc.200600512

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      Membrane fouling: Integration of nanofiltration in new applications is hampered by membrane fouling. To understand and control the fouling phenomenon, thorough membrane characterization is necessary. This study presents an overview of several physico-chemical characterization techniques, applied on commercial (see figure) and laboratory-made membranes.

    3. Kinetic Isotope Effects in Complex Reaction Networks: Formic Acid Electro-Oxidation (pages 380–385)

      Yan-Xia Chen, Martin Heinen, Zenonas Jusys and Rolf Jürgen Behm

      Article first published online: 31 JAN 2007 | DOI: 10.1002/cphc.200600520

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      Which way? Information obtained from kinetic measurements is the result of a complex combination of different reaction pathways. For formic acid electro-oxidation on Pt, the kinetic isotope effect (KIE) in a single reaction step (the formation of COad by C[BOND]H bond breaking) can be determined by in situ IR spectroscopy to be 1.9, independent of the potential, while the KIE in the dominant direct pathway (direct oxidation to CO2) is significantly higher (≈3, see figure).

    4. Interface Fermi Level Pinning at Contacts Between PEDOT: PSS and Molecular Organic Semiconductors (pages 386–390)

      Heiko Peisert, Andreas Petr, Lothar Dunsch, Thomas Chassé and Martin Knupfer

      Article first published online: 18 JAN 2007 | DOI: 10.1002/cphc.200600542

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      The injection barriers at interfaces between the conducting polymer PEDOT: PSS and model molecular organic semiconductors like phthalocyanines cannot be tuned by variation of the work function at either side of the interface (see figure). Such interfaces are characterized by charge-transfer processes and an associated Fermi level pinning, a situation that is very important for the understanding and design of organic devices.

    5. Implications of Molecular Orbital Symmetries and Energies for the Electron Delocalization of Inorganic Clusters (pages 391–398)

      Clémence Corminboeuf, R. Bruce King and Paul von Rague Schleyer

      Article first published online: 25 JAN 2007 | DOI: 10.1002/cphc.200600547

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      Contrasting magnetic properties of isostructural cages: Analysis of molecular orbital contributions to the electron delocalization of inorganic clusters through their effect on the nucleus-independent chemical shifts is presented. Isoelectronic or isostructural clusters (see picture) may exhibit surprisingly different magnetic properties. How can these contrasting properties be rationalized?

    6. One- and Two-Photon Singlet Oxygen Generation with New Fluorene-Based Photosensitizers (pages 399–404)

      Stephen J. Andrasik, Kevin D. Belfield, Mykhailo V. Bondar, Florencio E. Hernandez, Alma R. Morales, Olga V. Przhonska and Sheng Yao

      Article first published online: 17 JAN 2007 | DOI: 10.1002/cphc.200600568

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      Singlet oxygen: The spectral properties of new fluorene-based photosensitizers that undergo efficient 1O2 generation under 1 or 2 photon excitation (see figure) are investigated. These hydrophilic photosensitizers possess high singlet oxygen quantum yields making them well suited for two-photon photodynamic cancer therapy.

    7. Alternating Spin Chains: Controlled Assembly from Bimetallic Building Blocks and QMC Simulation of Spin Correlation (pages 405–417)

      Serhiy Demeshko, Guido Leibeling, Sebastian Dechert, Sebastian Fuchs, Thomas Pruschke and Franc Meyer

      Article first published online: 31 JAN 2007 | DOI: 10.1002/cphc.200600586

      Thumbnail image of graphical abstract

      A targeted construction strategy for S=1 alternating one-dimensional spin chains is developed on the basis of controlled linking of pre-organized azido- and pyrazolate-bridged bimetallic building blocks through additional azide bridges. The picture shows the NiN core of one of the chains and a comparison of experimental (symbols) and QMC (lines) magnetic properties.

    8. From Cloudy to Transparent: Chain Rearrangement in Hydrogen-Bonded Layer-by-Layer Assembled Films (pages 418–424)

      Shuguang Yang, Yongjun Zhang, Xiaoyan Zhang, Ying Guan, Jian Xu and Xiaoli Zhang

      Article first published online: 20 DEC 2006 | DOI: 10.1002/cphc.200600595

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      Clearing things up: Cloudy layer-by-layer films fabricated from poly(vinylpyrrolidone) and poly(acrylic acid) can be made transparent by annealing in acidic water. The transition from cloudy to transparent was monitored ex situ by using UV/Vis spectroscopy to measure the spectral absorbance in the range 300–1100 nm (see picture) and in situ by fluid atomic force microscopy. The factors that influence the degree of cloudiness are determined.

    9. Thermodynamics of the Decomposition Processes of Donor–Acceptor Complexes MX3⋅en⋅MX3 and MX3⋅en (pages 425–432)

      Cong Trinh, Alexey Y. Timoshkin and Gernot Frenking

      Article first published online: 19 DEC 2006 | DOI: 10.1002/cphc.200600603

      Thumbnail image of graphical abstract

      Decomposition theory: The gas-phase decomposition reactions of donor–acceptor complexes of Group 13 metal halides with ethylenediamine comprise dissociation into components and HX elimination (see picture). These reactions are studied theoretically at the B3LYP/LANL2DZ(d,p) level of theory. The complexes are predicted to be stable with respect to dissociation up to 640–1000 K.

    10. Two-Focus Fluorescence Correlation Spectroscopy: A New Tool for Accurate and Absolute Diffusion Measurements (pages 433–443)

      Thomas Dertinger, Victor Pacheco, Iris von der Hocht, Rudolf Hartmann, Ingo Gregor and Jörg Enderlein

      Article first published online: 31 JAN 2007 | DOI: 10.1002/cphc.200600638

      Thumbnail image of graphical abstract

      Absolute diffusion coefficients: Two-focus-FCS (2fFCS) is a powerful modification of fluorescence correlation spectroscopy. By using two overlapping foci with a well-defined distance (see figure), 2fFCS introduces an external length scale which allows for precise and absolute measurements of diffusion coefficients. This method is robust to optical and photophysical artefacts inherent to standard FCS.

    11. Adsorption, Diffusion and Desorption of Chlorine on and from Rutile TiO2{110}: A Theoretical Investigation (pages 444–451)

      Oliver R. Inderwildi and Markus Kraft

      Article first published online: 17 JAN 2007 | DOI: 10.1002/cphc.200600653

      Thumbnail image of graphical abstract

      Titania nanoparticle growth: The diffusion of chlorine on different TiO2{110} surfaces is investigated, with the aim of providing a better understanding of the formation of titania nanoparticles. The picture shows chlorine (green) diffusing into a defect site on stoichiometric TiO2{110} (Ti: silver; O: red).

    12. Comparison of Thermodynamic Properties of Coarse-Grained and Atomic-Level Simulation Models (pages 452–461)

      Riccardo Baron, Daniel Trzesniak, Alex H. de Vries , Andreas Elsener, Siewert J. Marrink and Wilfred F. van Gunsteren

      Article first published online: 8 FEB 2007 | DOI: 10.1002/cphc.200600658

      Thumbnail image of graphical abstract

      Thermodynamic data for liquid hydrocarbons and water is obtained at coarse-grained (CG) and atomic-level (AL) resolutions. The picture shows an example of coarse graining of the simulation model (a) and the fundamental thermodynamic quantities used to parameterize a simplified force field for MD simulations (b).

    13. Bending Energetics of Tablet-Shaped Micelles: A Novel Approach to Rationalize Micellar Systems (pages 462–472)

      L. Magnus Bergström

      Article first published online: 31 JAN 2007 | DOI: 10.1002/cphc.200600692

      Thumbnail image of graphical abstract

      The structural behavior of tablet-shaped micelles is theoretically investigated as a function of the three bending elasticity constants: spontaneous curvature (H0), bending rigidity (kc, see figure), and saddle-splay constant (equation image). Elongated micelles (large length-to-width ratio) form as the bending rigidity is lowered so as to approach the critical point at kc=0 whereas globular micelles (small length-to-width ratio) are expected to be present at large kc values.

    14. Reaction Pathways Involved in the Mechanism of AlIII Chelation with Caffeic Acid: Catechol and Carboxylic Functions Competition (pages 473–479)

      Christine Lapouge and Jean-Paul Cornard

      Article first published online: 21 DEC 2006 | DOI: 10.1002/cphc.200600620

      Thumbnail image of graphical abstract

      Competing complex sites: Process steps of reaction paths controlling the reactivity of the aluminium ion with a multi-site ligand are determined by DFT calculations. Chelate formation via complexation with both the catechol and carboxylic functions are investigated (see figure). The rate-determining step (RDS) that explains the regioselectivity of AlIII corresponds to the ring closure leading to chelate formation.

    15. Luminescent Eu(III) and Gd(III) Trisbipyridine Cryptates: Experimental and Theoretical Study of the Substituent Effects (pages 480–488)

      Dominique Guillaumont, Hervé Bazin, Jean-Marc Benech, Marion Boyer and Gérard Mathis

      Article first published online: 17 JAN 2007 | DOI: 10.1002/cphc.200600669

      Thumbnail image of graphical abstract

      Cryptic lanthanides: A joint experimental and theoretical study on luminescent lanthanide trisbipyridine cryptates (see picture) is presented. Time-dependent density functional theory is successfully applied to calculate the excited states of these large lanthanide complexes.

  5. Preview

    1. Top of page
    2. Cover Picture
    3. Graphical Abstract
    4. Minireview
    5. Articles
    6. Preview
    1. You have free access to this content
      Preview: ChemPhysChem 4/2007 (page 490)

      Article first published online: 8 FEB 2007 | DOI: 10.1002/cphc.200790006

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