Advanced Functional Materials

Cover image for Vol. 12 Issue 3

March, 2002

Volume 12, Issue 3

Pages 159–234

    1. Contents (pages 159–161)

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<159::AID-ADFM159>3.0.CO;2-I

    2. Online Manuscript Submission (page 163)

      P. Gregory

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<163::AID-ADFM163>3.0.CO;2-1

      Online submission of manuscripts via the Advanced Functional Materials home page is now possible. How the system work, its advantages over conventional postal submission, and the simple steps involved in submitting a manuscript online are described. It is anticipated that this new submission process will be adopted very quickly.

    3. 1,2-Dithienylethene Photochromes and Non-destructive Erasable Memory (pages 167–173)

      A.J. Myles and N.R. Branda

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<167::AID-ADFM167>3.0.CO;2-M

      Non-destructive, erasable memory based on dithienylethene systems (see Figure) has been investigated. The two readout signals highlighted are luminescence and optical rotation. The use of ring-opening metathesis polymerization (ROMP) to fabricate well-ordered photochromic homopolymers is also described.

    4. Synthesis of a Stable Metallic Niobium Oxide Molecular Sieve and Subsequent Room Temperature Activation of Dinitrogen (pages 174–178)

      M. Vettraino, X. He, M. Trudeau, J.E. Drake and D.M. Antonelli

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<174::AID-ADFM174>3.0.CO;2-U

      Cleavage of dinitrogen with the aid of molecular sieves has been achieved! Because of their controlled porosity and high surface areas molecular sieves are ideal candidates for model studies of nitrogen reduction and catalytic nitrogen incorporation into organic compounds. The formation of a low-valent metallic oxide coating on the internal surface of a mesoporous oxide is shown both in the Figure and on the front cover of this issue.

    5. Selective Deposition of Rod-like Phthalocyanine Aggregates on Au Surfaces Patterned with a Combination of Microcontact Printing and Electropolymerization (pages 179–186)

      R.A.P. Zangmeister, D.F. O’Brien and N.R. Armstrong

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<179::AID-ADFM179>3.0.CO;2-A

      Copper phthalocyanine (Pc) aggregate patterned thin films (see inside front cover) are created by means of capillary flow of chloroform solutions into micrometer-dimension hydrophobic/hydrophilic channels (fabricated by a combination of microcontact printing and electropolymerization of polyphenoxides). The Figure shows the definition of the polyphenoxide channel walls and termination of the patterned Pc film formed by capillary flow.

    6. Determining Protein Size Using an Electrochemically Machined Pore Gradient in Silicon (pages 187–191)

      B.E. Collins, K.-P.S. Dancil, G. Abbi and M.J. Sailor

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<187::AID-ADFM187>3.0.CO;2-E

      Variable pore sizes in porous silicon films (see Figure) can be obtained by an inhomogeneous electrochemical etching technique. The simultaneous separation and detection of a protein in a nanomachined silicon matrix is demonstrated. Gating of the response by adjustment of pH below and above the isoelectric point of the protein can also be achieved.

    7. Fluorene-Based Copolymers for Red-Light-Emitting Diodes (pages 192–196)

      S. Beaupré and M. Leclerc

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<192::AID-ADFM192>3.0.CO;2-U

      Red and red–orange light-emitting polymers have been fabricated by Suzuki coupling between functionalized fluorenes and oligothiophenes (the Figure shows the chemical structure of a red-light-emitting polymer). The copolymers exhibit relatively high glass-transition temperatures and interesting optical and electrochemical properties.

    8. Silica–Carbon Nanocomposites—A New Concept for the Design of Solar Absorbers (pages 197–202)

      Y. Mastai, S. Polarz and M. Antonietti

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<197::AID-ADFM197>3.0.CO;2-A

      Carbon–silica nanocomposites are effective solar energy absorbers with little energy loss to IR radiation. Two synthetic routes to such composites are reported: hydrolysis of tetramethylorthosilane (TMOS) in the presence of a cyclodextrin, and loading of porous silica with a phenol epoxy resin, both followed by thermal carbonization. The Figure shows a TEM image of a cyclodextrin-derived composite.

    9. Symmetric and Asymmetric Conjugated 3,3′-Bipyridine Derivatives as a New Class of Third-Order NLO Chromophores with an Enhanced Non-resonant, Nonlinear Refractive Index in the Picosecond Range (pages 203–208)

      F. Chérioux, A.-J. Attias and H. Maillotte

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<203::AID-ADFM203>3.0.CO;2-L

      A new class of organic compounds with large nonlinear indices in solution is presented: 6,6′-disubstituted 3,3′-biphenyls (see Figure for general formula). In symmetric molecules of this type, no two-photon absorption between ground and first excited state can be detected. This gives more freedom to optimize the electronic structure, and can lead to a better (NLO efficiency/transparency) trade-off in the near-IR.

    10. Chiral Perylene Bisimide–Melamine Assemblies: Hydrogen Bond-Directed Growth of Helically Stacked Dyes with Chiroptical Properties (pages 209–218)

      C. Thalacker and F. Würthner

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<209::AID-ADFM209>3.0.CO;2-Y

      Self-aggregation and hydrogen bond-directed superstructure formation with a perylene bisimide dye (see Figure) were investigated for melamines bearing two or four alkyl chains. In addition to the influence of the substituents of the building blocks, it is demonstrated that it is possible to induce chiroptical properties of the perylene bisimide chromophores by self- assembly with chiral melamines.

    11. Synthesis and Characterization of Uniform Nanowires of Trigonal Selenium (pages 219–227)

      B. Gates, B. Mayers, B. Cattle and Y. Xia

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<219::AID-ADFM219>3.0.CO;2-U

      Highly pure trigonal selenium nanowires (see Figure) have been obtained by soft solution processing. Spectral measurements suggest a blue-shift in the bandgap and exciton peaks for these t-Se nanowires when their mean diameter is decreased. The absence of kinks and related defects in these selenium nanowires makes this new class of 1D nanostructures particularly useful in the fabrication of electronic, optical, or electromechanical devices.

    12. Boron Nitride Fibers Prepared from Symmetric and Asymmetric Alkylaminoborazines (pages 228–234)

      B. Toury, P. Miele, D. Cornu, H. Vincent and J. Bouix

      Version of Record online: 7 MAR 2002 | DOI: 10.1002/1616-3028(200203)12:3<228::AID-ADFM228>3.0.CO;2-U

      Hexagonal boron nitride (h-BN) fibers should be useful for the preparation of composites similar to “carbon/carbon” materials but suitable for higher-temperature applications. The thermolysis of symmetric and asymmetric alkylaminoborazines (see Figure for an example) to polyborazines is reported, along with their subsequent processing to polyborazine filaments and h-BN fibers. The performance of some of the fibers arouses interest in this preparative route.