Optical properties and electrical transport of thin films of terbium(III) bis(phthalocyanine) on cobalt

• Peter Robaschik,
• Pablo F. Siles,
• Daniel Bülz,
• Peter Richter,
• Manuel Monecke,
• Michael Fronk,
• Svetlana Klyatskaya,
• Daniel Grimm,
• Oliver G. Schmidt,
• Mario Ruben,
• Dietrich R. T. Zahn and
• Georgeta Salvan

Beilstein J. Nanotechnol. 2014, 5, 2070–2078, doi:10.3762/bjnano.5.215

• crystalline grains in the film [29]. A decrease in the hole mobility values with increasing film thickness is therefore at a first glance surprising. However, considering the anisotropic hole transport in the phthalocyanines (with higher mobility in the direction of the π–π stacking in a molecular crystal

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• possibility to obtain stimuli-responsive precipitation or dispersion of CNTs. Keywords: carbon nanotubes; non-covalent functionalization; π-stacking; reversible dispersion/precipitation; Introduction Carbon nanotubes (CNTs) are hollow cylindrical tubes with nanometer scale diameters and lengths up to a few

• , to ensure a good CNTs dispersion. Landi et al. [42] obtained a dispersion stable for days by sonicating CNTs with N,N-diethylacetamide (DEA) and imputed the stability of the dispersion to synergistic effective polar and π-stacking interactions. As a matter of fact solvents characterized by either

• elected solvent. In particular both small molecules and high weight polymers have been used as dispersants. Aromatic molecules have a strong affinity for graphitic surfaces via π–stacking. The adsorption of different polycyclic aromatic hydrocarbons (PAH) such as pyrene, anthracene, tetracene and

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• ] or supramolecularly, by π–π stacking and/or van der Waals interactions [14], the latter methodology suffers from weak interactions between the two species (i.e., graphene and organic units), which often leads to a loss of the organic moiety. Apparently, covalent functionalization of exfoliated

DFT study of binding and electron transfer from colorless aromatic pollutants to a TiO₂ nanocluster: Application to photocatalytic degradation under visible light irradiation

• Corneliu I. Oprea,
• Petre Panait and
• Mihai A. Gîrţu

Beilstein J. Nanotechnol. 2014, 5, 1016–1030, doi:10.3762/bjnano.5.115

• contrast, when the binding is of the (h)-type the ring is tilted almost parallel to the surface (τ = 13.6°), reminding of π stacking interactions. In the case of SA adsorbed on TiO2 previous studies claimed that in the salicylate complex formed at the interface both substituent groups are involved, which

Enhancement of photocatalytic H₂ evolution of eosin Y-sensitized reduced graphene oxide through a simple photoreaction

• Weiying Zhang,
• Yuexiang Li,
• Shaoqin Peng and
• Xiang Cai

Beilstein J. Nanotechnol. 2014, 5, 801–811, doi:10.3762/bjnano.5.92

• through π–π stacking [19][20][21] of the xanthene moiety (the fused ring) of EY with sp2 π-conjugated domains of graphene. Table 2 lists the amount of adsorbed EY on the surface of RGOx. Before the irradiation, the adsorption amount of EY on the GO surface is 11.7 μmol g−1. After irradiation of GO for 4

• , 12 and 24 h, the adsorption amount increases to 15.0, 32.7 and 74.3 μmol g−1, respectively. This is because the sp2 domains of RGOx increase with the reaction time (see Mechanism section, Scheme 1). As a result, the π–π stacking interaction between EY and RGO becomes stronger. To further confirm the

• photo-induced electron transfer from the excited dye molecules to RGOx. The slight blue shift suggests that an intermolecular π-π stacking interaction between RGO24 and EY is stronger than the interaction between GO and EY [20]. To further confirm the increased ability to transfer electrons between RGOx

DNA origami deposition on native and passivated molybdenum disulfide substrates

• Xiaoning Zhang,
• Masudur Rahman,
• David Neff and
• Michael L. Norton

Beilstein J. Nanotechnol. 2014, 5, 501–506, doi:10.3762/bjnano.5.58

• pairing responsible for origami structure formation and maintenance and are therefore unsuitable substrates for DNA origami deposition and patterning. For example, the folded structures are lost when they are deposited onto a graphene surface, because of π–π stacking between the single-stranded DNA and

• ordered array. These results are of crucial importance, as they support the hypothesis that the van der Waals interaction between MoS2 and the DNA in the origami is of sufficient strength to destabilize the hydrogen bonds as well as the π–π stacking interactions in the relatively short duplex regions

Morphological characterization of fullerene–androsterone conjugates

• Alberto Ruiz,
• Margarita Suárez,
• Nazario Martin,
• Fernando Albericio and
• Hortensia Rodríguez

Beilstein J. Nanotechnol. 2014, 5, 374–379, doi:10.3762/bjnano.5.43

• representative analysis of each sample, several areas of the grids were observed. The two diastereomeric pairs (Ia,b and IIa,b) showed spherical self-assembly due to the non-covalent interactions present in these compounds, i.e., van der Waals forces, hydrogen bonding, hydrophilic/hydrophobic interactions, π–π

• stacking interactions, and donor–acceptor interactions. The aggregation behavior of these compounds was associated to the hydrophobic nature of the C60 core as the main attractive force, furthermore, the presence of different polar groups, carbonyl and acetoxy group for Ia,b and IIa,b respectively, in the

Dipole-driven self-organization of zwitterionic molecules on alkali halide surfaces

• Laurent Nony,
• Franck Bocquet,
• Franck Para,
• Frédéric Chérioux,
• Eric Duverger,
• Frank Palmino,
• Vincent Luzet and
• Christian Loppacher

Beilstein J. Nanotechnol. 2012, 3, 285–293, doi:10.3762/bjnano.3.32

• intermolecular π-stacking of the organic molecules. Although for certain molecules π-stacking can lead to the formation of one-dimensional wires [3], in general, for organic–inorganic heteroepitaxy (OIHE) on insulating substrates the growth mode is often governed by a dewetting process [4] as the MM interaction

An NC-AFM and KPFM study of the adsorption of a triphenylene derivative on KBr(001)

• Antoine Hinaut,
• Adeline Pujol,
• Florian Chaumeton,
• David Martrou,
• André Gourdon and
• Sébastien Gauthier

Beilstein J. Nanotechnol. 2012, 3, 221–229, doi:10.3762/bjnano.3.25

• strong intermolecular interaction due to π-stacking. Keywords: atomic force microscopy; insulating surfaces; Kelvin force probe microscopy; molecular adsorption; Introduction The study of molecular adsorption on atomically clean, well-defined surfaces of bulk insulators is progressing rapidly due to

• energy, which should exceed 1.8 − 0.4 = 1.4 eV. This is indeed the case. The interaction energy between two free HCPTP, calculated with the COMPASS force field when the triphenylene cores are in a π-stacking configuration, is on the order of 2.5 eV, well above this threshold. MLv is then more stable than

Molecular-resolution imaging of pentacene on KCl(001)

• Julia L. Neff,
• Jan Götzen,
• Enhui Li,
• Michael Marz and
• Regina Hoffmann-Vogel

Beilstein J. Nanotechnol. 2012, 3, 186–191, doi:10.3762/bjnano.3.20

• interaction is indeed weak compared to the intermolecular interaction. Figure 1c illustrates the upright ordering of the molecules. For comparison we have added a top-view sketch of the well-known bulk phase, showing the herringbone arrangement that the molecules assume to optimize the π-stacking (Figure 1d

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

• . For the in-plane GIWAXD pattern, one noticeable diffraction peak associated with the (010) diffraction was observed. The diffraction peak corresponds to the π–π* stacking of the P3HT thiophene ring and was parallel to the y-axis, i.e., the nanofiber direction. Again, the (010) peak was diminished when

An MCBJ case study: The influence of π-conjugation on the single-molecule conductance at a solid/liquid interface

• Wenjing Hong,
• Hennie Valkenier,
• Gábor Mészáros,
• David Zsolt Manrique,
• Artem Mishchenko,
• Alexander Putz,
• Pavel Moreno García,
• Colin J. Lambert,
• Jan C. Hummelen and
• Thomas Wandlowski

Beilstein J. Nanotechnol. 2011, 2, 699–713, doi:10.3762/bjnano.2.76

• slightly higher than the molecular length of AC (2.7 nm). We propose that the strong gold–thiole bond leads to the “pulling-out” of surface gold atoms just before the breaking of the molecular junction. The low-conductance feature is attributed to π-stacking interactions between two molecules attached only

Self-organizing bioinspired oligothiophene–oligopeptide hybrids

• Alexey K. Shaytan,
• Eva-Kathrin Schillinger,
• Elena Mena-Osteritz,
• Sylvia Schmid,
• Pavel G. Khalatur,
• Peter Bäuerle and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2011, 2, 525–544, doi:10.3762/bjnano.2.57

• der Waals interactions of the interdigitating long alkyl side chains. Furthermore, the planar conjugated thiophene backbone is well known to interact by π–π stacking to form larger crystalline structures. With respect to the peptide part, the L-valine-L-threonine (Val–Thr)3 sequence effectively forms

• twisted short fibers of 1' on the mica substrate. Due to the hybrid nature of 1', two opposing intermolecular interactions could dominate the self-assembly process, namely H-bonding and π–π stacking. Thus, a solvent-guided strategy was employed in order to gain control over the self-assembly process

• various technological applications, the most important question concerns the arrangement of the conjugated thiophene moieties and the interplay between π−π stacking and β-sheet formation. As spacing between the molecules implied by the β-sheet structure corresponds to 4.8−5 Å, whereas the spacing between

Novel acridone-modified MCM-41 type silica: Synthesis, characterization and fluorescence tuning

• Maximilian Hemgesberg,
• Gunder Dörr,
• Yvonne Schmitt,
• Andreas Seifert,
• Zhou Zhou,
• Robin Klupp Taylor,
• Sarah Bay,
• Stefan Ernst,
• Markus Gerhards,
• Thomas J. J. Müller and
• Werner R. Thiel

Beilstein J. Nanotechnol. 2011, 2, 284–292, doi:10.3762/bjnano.2.33

• also dependent on the boiling point of the sol–gel solution. Thus, the addition of larger amounts of volatile organic solvents such as THF to the aqueous phase often prevents the formation of highly ordered mesoporous structures [16]. On the other hand, the π-stacking of large aromatics generally

Oriented growth of porphyrin-based molecular wires on ionic crystals analysed by nc-AFM

• Thilo Glatzel,
• Lars Zimmerli,
• Shigeki Kawai,
• Ernst Meyer,
• Leslie-Anne Fendt and
• Francois Diederich

Beilstein J. Nanotechnol. 2011, 2, 34–39, doi:10.3762/bjnano.2.4

• their intermolecular π–π stacking. Experimental Experiments were performed under ultrahigh vacuum (UHV) conditions with a base pressure below 10−10 mbar using a home built non-contact atomic force microscope operated at rt [39]. In the nc-AFM mode, the tip-sample distance is usually controlled by

• of molecules at those edges. The leftmost molecule (i) in (d) is turned by 45° so that the core is oriented along the [110] direction. This orientation does not allow π–π stacking along the direction of the step edges. The molecule in the middle (ii) is tilted by 45° to the surface, making it fit