Nanoscopic surfactant behavior of the porin MspA in aqueous media

• Ayomi S. Perera,
• Hongwang Wang,
• Tej B. Shrestha,
• Deryl L. Troyer and
• Stefan H. Bossmann

Beilstein J. Nanotechnol. 2013, 4, 278–284, doi:10.3762/bjnano.4.30

• and octameric oligomers [13]. In the near future, designer proteins with tailored biophysical properties will become increasingly available [14], and therefore, the influence of temperature on their supramolecular aggregation behavior will become more significant. Recently, the temperature dependence

Plasmonic oligomers in cylindrical vector light beams

• Mario Hentschel,
• Jens Dorfmüller,
• Harald Giessen,
• Sebastian Jäger,
• Andreas M. Kern,
• Kai Braun,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2013, 4, 57–65, doi:10.3762/bjnano.4.6

• , a project which has, to the best of our knowledge, not been attempted so far. Keywords: near-field microscopy; oligomers; plasmons; radial and azimuthal polarization; Introduction Plasmonics is the optics of metal nanoparticles. If an external light field impinges on a metal nanoparticle

• as cylindrical vector beams, is a simple task. Plasmonic oligomers Originally, we intended to utilize split-ring resonators (SRR) as magnetic atoms. These U-shaped nanostructures support a plasmonic mode which is associated with a strong magnetic moment. Arranging SRRs in a chain and thus coupling

• tunable collective modes, which justify studying these kinds of plasmonic artificial molecules themselves in detail, even under linearly polarized light [12][13][14][15][16]. In the following we briefly review earlier work on plasmonic oligomers [13]. In order to investigate the evolution of the coupling

Structural and electronic properties of oligo- and polythiophenes modified by substituents

• Simon P. Rittmeyer and
• Axel Groß

Beilstein J. Nanotechnol. 2012, 3, 909–919, doi:10.3762/bjnano.3.101

• oligo- and polythiophenes As a first step and as a reference, we determined the properties of unsubstituted oligo- and polythiophenes. All oligomers were modeled by using a sufficiently large box in three dimensions to avoid intermolecular interaction due to the use of a periodic DFT code. Note that in

• the unsubstituted oligomers listed in Table 1, the previously mentioned problem of GGA-DFT when it comes to bandgaps is obvious. The calculated values are about 1 eV smaller than those measured by Diaz et al. [39]. Yet, the trend that the width of the HOMO–LUMO gap decreases with increasing size of

• already mentioned flattening effect of a growing chain length also found in DFT calculations for other large oligomers [27][31]. It also agrees with the results of Azumi et al. [40], who found a planar structure for the crystalline penta- and heptamer by X-ray diffraction. The calculated bond lengths are

Surface functionalization of aluminosilicate nanotubes with organic molecules

• Wei Ma,
• Weng On Yah,
• Hideyuki Otsuka and
• Atsushi Takahara

Beilstein J. Nanotechnol. 2012, 3, 82–100, doi:10.3762/bjnano.3.10

• spacers consisting of –CH2CH2– and P=O(OH)2 (Scheme 1). Thiophene oligomers have been extensively studied in recent years due to their excellent optic properties. It has been reported that thiophene oligomers exhibit high quantum yields of photoluminescence, both in solution as well as the solid state

X-ray spectroscopy characterization of self-assembled monolayers of nitrile-substituted oligo(phenylene ethynylene)s with variable chain length

• Hicham Hamoudi,
• Ping Kao,
• Alexei Nefedov,
• David L. Allara and
• Michael Zharnikov

Beilstein J. Nanotechnol. 2012, 3, 12–24, doi:10.3762/bjnano.3.2

• , packing density, molecular orientations, and molecular conformations; and yet in many cases these characteristics are neither precisely controlled nor measured, but simply assumed to be similar to those of other types of molecules and that they do not vary with different lengths of oligomers in the same

• series. Considering the variety of electrically functional molecules of interest in molecular electronics, the class of molecules based on simple oligomers of phenylene–ethynylene units is of particular importance for several reasons. First, the OPE chain is one of the most effective conductors among the

STM study on the self-assembly of oligothiophene-based organic semiconductors

• Elena Mena-Osteritz,
• Marta Urdanpilleta,
• Erwaa El-Hosseiny,
• Berndt Koslowski,
• Paul Ziemann and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 802–808, doi:10.3762/bjnano.2.88

• ordering on the substrate. Keywords: 2-D crystals; functionalized oligothiophenes; H-bonding; intermolecular interaction; scanning tunneling microscopy; Introduction In the last few decades conjugated organic polymers and oligomers have attracted a broad interest due to their excellent electronic and

• -molecule organic devices have restored huge interest in structurally well-defined and therefore monodisperse, crystalline oligomers [8]. The method of choice to investigate the ordering of organic semiconductors adsorbed on flat metallic surfaces, at the desired molecular level in the subnanometer range

• shorter oligomers. This phenomenon can be explained by a decrease in diffusivity as the size of the oligomers increase. However, the adsorption–desorption dynamics at the surface and the observed Ostwald ripening [21][22] lead to an almost perfect monolayer with time. The arrangement of the molecules

Optical properties of fully conjugated cyclo[n]thiophenes – An experimental and theoretical approach

• Elena Mena-Osteritz,
• Fan Zhang,
• Günther Götz,
• Peter Reineker and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 720–726, doi:10.3762/bjnano.2.78

• In the last few decades organic conjugated polymers and oligomers, in particular poly- and oligothiophenes, have attracted a broad interest due to their excellent electronic and transport properties in the solid state, which allow their application in a variety of organic-electronic devices, such as

• conjugated chain [5][6][7][8]. However, in particular for the shorter oligomers, end-effects imposed by the end groups perturb structure–property correlations, whereas for longer derivatives saturation of, e.g., optical transitions occurs leading to a limiting value. In this respect, 2D macrocyclic systems

• more or less well-pronounced torsion angles between the thiophene rings. This is in accordance with the behavior of the linear oligomers, which as well show a more pronounced aromatic structure in their ground state. In both series the extinction coefficient increases with increasing macrocyclic ring

Inorganic–organic hybrid materials through post-synthesis modification: Impact of the treatment with azides on the mesopore structure

• Miriam Keppeler,
• Jürgen Holzbock,
• Johanna Akbarzadeh,
• Herwig Peterlik and
• Nicola Hüsing

Beilstein J. Nanotechnol. 2011, 2, 486–498, doi:10.3762/bjnano.2.52

• by narrow mesopore size distributions, high specific surface areas and large pore volumes, is the application of cooperative self-assembly processes between supramolecular aggregates of organic molecules, oligomers or polymers and inorganic species such as alkoxysilanes for silica-based materials [4

Platinum nanoparticles from size adjusted functional colloidal particles generated by a seeded emulsion polymerization process

• Nicolas Vogel,
• Ulrich Ziener,
• Achim Manzke,
• Alfred Plettl,
• Paul Ziemann,
• Johannes Biskupek,
• Clemens K. Weiss and
• Katharina Landfester

Beilstein J. Nanotechnol. 2011, 2, 459–472, doi:10.3762/bjnano.2.50

• amount of monomer added for small monomer excesses. Hence, the degree of polymerization is low, and oligomers are formed that reside in the aqueous phase. These oligomers are seen in the SEM images in Figure 1c and Figure 1d as an undefined film covering the colloidal particles, appearing as bright seams

• determined for 5-fold and 20-fold monomer excess, we estimate values between 10 and 25 wt % relative to the monomer. At higher quantities of initiator, the resulting particle sizes decrease (cf. Figure 2a) as a result of insufficient polymerization leading to oligomers that remain in the water phase, as seen

Septipyridines as conformationally controlled substitutes for inaccessible bis(terpyridine)-derived oligopyridines in two-dimensional self-assembly

• Daniel Caterbow,
• Daniela Künzel,
• Michael G. Mavros,
• Axel Groß,
• Katharina Landfester and
• Ulrich Ziener

Beilstein J. Nanotechnol. 2011, 2, 405–415, doi:10.3762/bjnano.2.46

• ], bithiophene–fluorenone conjugated oligomers [20], a 2,6-di(acetylamino)pyridine substituted conjugated module [21], and a molecular hexapod having a benzene core and six oligo(p-phenylene vinylene) legs [22]. The conformers can have an impact on the expression or suppression of chirality of the supramolecular

Characterization of protein adsorption onto FePt nanoparticles using dual-focus fluorescence correlation spectroscopy

• Pauline Maffre,
• Karin Nienhaus,
• Faheem Amin,
• Wolfgang J. Parak and
• G. Ulrich Nienhaus

Beilstein J. Nanotechnol. 2011, 2, 374–383, doi:10.3762/bjnano.2.43

• -cooperative case, whereas apoE4 was observed to bind to the NPs in a cooperative manner, with n = 1.4. This result may be related to the known tendency of apoE4 to form oligomers in solution [41]. Apparently, apoE4 molecules have interfaces by which they can mutually exert attractive interactions

• at the lowest protein concentrations studied. All protein solutions were prepared by repeated dilution of a single stock solution. The apoE4 dilution series was prepared 2 h before mixing with the NPs to allow the sample to equilibrate between monomers and oligomers [41]. The experiments with apoA-I

Organic–inorganic nanosystems

• Paul Ziemann

Beilstein J. Nanotechnol. 2011, 2, 363–364, doi:10.3762/bjnano.2.41

• , doped π-conjugated oligomers and polymers play an important role due to their semiconducting behavior. As in standard electronics, the combination of p- and n-doped organic components leads to device applications such as organic light emitting diodes (OLED), organic field effect transistors (OFET) and

Detection of interaction between biomineralising proteins and calcium carbonate microcrystals

• Hanna Rademaker and
• Malte Launspach

Beilstein J. Nanotechnol. 2011, 2, 222–227, doi:10.3762/bjnano.2.26

• of perlucin has saccharide oligomers bound to these sites. In MALDI-MS (matrix-assisted laser desorption/ionization mass spectroscopy) of perlucin [10] variable molecular weights of perlucin are detectable, which can be related to a 10 amino acid repeat at the C-terminus being present in various