Advanced Materials

Cover image for Advanced Materials

November 1993

Volume 5, Issue 11

Pages 792–868

  1. Masthead

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Communications
    7. Research News
    8. Book Reviews
    1. Masthead (page 792)

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051101

  2. Essay

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Communications
    7. Research News
    8. Book Reviews
    1. Advanced materials: An emerging industrial sector (pages 793–795)

      Dr. Martin Bangemann

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051102

      European Community support for research on advanced materials is provided within the four-year Framework programs for research and technological development. In particular, the current program “Industrial and Materials Technologies–BRITE/Euram II” is aimed at establishing the necessary technological base for the development of new products and processes. The Vice President of the Commission of the European Communities describes his view of the present market and future prospects for advanced materials, taking restraints imposed by a need to protect the environment into consideration.

  3. Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Communications
    7. Research News
    8. Book Reviews
    1. Functionalized langmuir–blodgett films—toward the construction of molecular devices (pages 796–803)

      Dr. Hiroaki Tachibana and Dr. Mutsuyoshi Matsumoto

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051103

      Control of the orientation of component molecules in Langmuir–Blodgett (LB) films is important for their use in molecular electronics. Cyclodextrins can be given a particular orientation at the air-water interface by introducing long alkyl chains through the amino, sulfinyl, and sulfide groups (see Figure). This article reviews progress in molecular-component and supramolecular LB films and photochemical switching systems constructed from them.

    2. Molecular materials for second-order nonlinear optical applications (pages 804–815)

      Dr. Seth R. Marder and Dr. Joseph W. Perry

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051104

      Strategies for the optimization of molecular second-order nonlinearities have emerged over the past few years, but significant questions still remain. This review highlights recent conceptual advances in the field of nonlinear optical molecular materials, concentrating on design criteria for the molecules themselves, e.g., the influence of resonance structures, bond length alternation, and reduced aromaticity, and the use of organometallic compounds and octupolar molecules. Factors affecting the properties of bulk materials composed of such molecules are also discussed.

  4. Materials Forum

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Communications
    7. Research News
    8. Book Reviews
    1. Materials Forum (pages 815–856)

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051105

  5. Communications

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Communications
    7. Research News
    8. Book Reviews
    1. Electronic origin of scanning tunneling microscopy images and carbon skeleton orientations of normal alkanes adsorbed on graphite (pages 817–821)

      Weigen Liang, Prof. Myung-Hwan Whangbo, Aleksander Wawkuschewski, Prof. Hans-Joachim Cantow and Dr. Sergei N. Magonov

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051106

      STM images of organic insulating molecules adsorbed on conducting substrates can only be understood if their electronic origin is known. Images of normal alkanes on graphite (n-C36H74) is shown in the Figure are interpreted here on the basis of their partial electron density plots ρ(r0,ef), demonstrating that the linear alkanes can “tumble” and change their orientation with respect to the graphite surface.

    2. STM study of molecular order and defects in the layers of cycloalkanes (CH2)48 and (CH2)72 adsorbed on graphite (pages 821–826)

      Aleksander Wawkuschewski, Prof. Hans-Joachim Cantow, Dr. Sergei N. Magonov, Prof. Martin Möller, Weigen Liang and Prof. Myung-Hwan Whangbo

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051107

      Cycloalkanes adsorbed on graphite, unlike the normal alkanes considered in the preceding contribution, cannot undergo a tumbling motion and change their orientation with respect to the graphite surface. The orientation of the cycloalkanes as revealed by STM images is reported and lamella defects are identified. An answer is also given to the question of how many adlayers are seen by STM, which is very important in the interpretation of superstructure patterns.

    3. Mass sensitive detection of solvent vapors with calix[n]arenes—conformational adaptation to the analyte (pages 826–829)

      Prof. Franz L. Dickert and Oliver Schuster

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051108

      Calixarenes have a hig molecular flexibility, facilitating an optimized adaptation to the shape of a large variety of guest molecules. Large substituents result in conformationally rigid compounds (Figure) but other calixarenes are ideal for coatings exhibiting high chemical sensitivity.

    4. Alloyed deuterated copper-DCNQI salts: Phase transitions and reentry of conductivity, giant hysteresis effects, and coexistence of metallic and semiconducting modes (pages 829–834)

      Dagmar Bauer, Dr. Jost Ulrich von Schütz, Dr. Hans Christoph Wolf, Prof. Siegfried Hünig, Klaus Sinzger and Dr. Reinhard K. Kremer

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051109

      The copper salts of DCNQI (N, N'-dicyanoquinonediimine), quasi-three-dimensional systems, show three possible modes of behavior at low temperatures: they remain metallic, they undergo a phase transition, or they have a suppressed phase transition, as is the case for alloyed copper salts. Deuteration of these salts can change their behavior. Alloyed deuterated copper-DCNQI salts have been investigated using electron spin resonance, susceptibility, and conductivity measurements, revealing a reduction of the phase transition temperature[BOND]with hystersis[BOND]and reentry effects in the conductivity.

    5. The deformability of the thiophene ring: A key to the understanding of the conformational properties of oligo- and polythiophenes (pages 834–838)

      Dr. Giovanna Barbarella, Massimo Zambianchi, Prof. Alessandro Bongini and Prof. Luciano Antolini

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051110

      Oligothiophenes in solution and in the solid state have different conformational properties, as can be concluded from the spectroscopic and theoretical data and X-ray structure of three di- and tetramethyl α-conjugated quaterthiophenes (see Figure) reported here.

    6. Recording of transient gratings using the short lived bacteriorhodopsin photocycle intermediates (pages 838–842)

      Dr. Shuguang Wu, Prof. Christoph Bräuchle and Prof. Mostafa A. El-Sayed

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051111

      Bacteriorhodopsin, a light-transducing protein in the purple membrane of Halobacterium halobium, has unique properties that make it a potentially attractive material for use in optical imaging and processing. A transient diffraction grating based on the K intermediate of the bacteriorhodopsin photocycle has been produced on the nanosecond time scale. The diffraction efficiency, which would be sufficient for pattern recognition for example, was measured and the intensity dependence assessed.

    7. Gas phase molecular modeling of liquid crystals: Electro-optical anisotropies (pages 842–848)

      Dr. Matthias Bremer and Dr. Kazuaki Tarumi

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051112

      Molecular modeling of liquid crystals is important as it provides information without the need for chemical synthesis. The first ever quantitative correlation of semiempirically obtained quantities with electro-optical parameters measured in 80 bulk liquid crystals is reported here. The Figure shows the calculated relative energy of an LC as a function of two torsion angles.

    8. Molecular recognition of alkali-ions by crown-ether-functionalized poly(alkylthiophenes) (pages 848–853)

      Dr. Peter Bäuerle and Stefan Scheib

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051113

      New crown-ether-functionalized alkyl(oligothiophene)s (see Figure) have been synthesized and electropolymerized to alkali metal ion sensitive poly(alkylthiophene)s. It is shown for the first time that the redox chemistry of a conducting polymer is strongly influenced by the specific host-guest interaction, although the crown ether units are not π-conjugated to the conducting backbone but separated by an insulating oxa-alkyl chain.

    9. The Diels–Alder adduct of C60 and 4,5-dimethoxy-o-quinodimethane—synthesis, crystal structure, and donor–acceptor behavior (pages 854–856)

      Pavel Belik, Andreas Gügel, Alexander Kraus, Jochen Spickermann, Dr. Volker Enkelmann, Dr. Georg Frank and Prof. Klaus Müllen

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051114

      Covalent linking of C60 to electron donors is expected to create attractive substrates for the study of electron or energy transfer. The successful synthesis of a 4,5-dimethoxy-o-quinodimethane-C60 adduct is described. The unique crystal structure has been determined and the bandgap measured by ESCA. One of the most interesting features of the crystal structure of the mono-adduct is the close contact of one of the methoxy groups to a neighboring C60, leading to the formation of a chain of interacting fullerene cages.

  6. Research News

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Communications
    7. Research News
    8. Book Reviews
    1. Microwave syntheses of inorganic materials (pages 857–859)

      Prof. D. Michael P. Mingos

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051115

      Microwave processing is a relatively new technique for chemical syntheses, and it is proving to be more widely applicable than could have been imagined even just five years ago. After a brief introduction to the theory, this article presents the advantages of microwave dielectric heating and discusses applications to solid-state oxides, superconductors, fine metal powders, and semiconductors. The speed of the reaction is often impressive, and the phenomenon of “thermal runaway”, despite its name, can be helpful rather than a nuisance.

    2. Fullerene polymers (pages 859–861)

      Dr. Andreas Hirsch

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051116

      Polymeric fullerene materials come in tree main types: “pendant”, where C60 is attached to the side chain of a polymer (see Figure) or to the surface of a solid, “dendritic”, and “in-chain”, where the fullerene forms part of the main chain. The synthesis of the various types is discussed and their expected unique properties described.

    3. New HTSCs—still far below room temperature (pages 862–864)

      Dr. Peter Majewski

      Article first published online: 29 OCT 2004 | DOI: 10.1002/adma.19930051117

      Tcs climb, but although superconductivity at liquid nitrogen temperatures has become almost commonplace there is still a long way to go before room temperature is reached. Recent progress is discussed in the optimization of the preparation parameters and superconducting properties of the “classical” high-temperature superconductors (HTSCs) of the YBCO and BSCCO series, and possible future directions in the search for new HTSCs (preferably ones that do not include toxic element such as Hg) are suggested.

  7. Book Reviews

    1. Top of page
    2. Masthead
    3. Essay
    4. Reviews
    5. Materials Forum
    6. Communications
    7. Research News
    8. Book Reviews

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