The role of ligands in coinage-metal nanoparticles for electronics

• Ioannis Kanelidis and
• Tobias Kraus

Beilstein J. Nanotechnol. 2017, 8, 2625–2639, doi:10.3762/bjnano.8.263

• thiolates increased when decreasing the number of saturated units [58]. A different study found that π–π-stacking of phenyl groups in films of phenylethylthiolate-stabilized gold nanoparticles determined the interparticle separation and regulated charge transfer. The short ligand chain and the aromatic

Carbon nano-onions as fluorescent on/off modulated nanoprobes for diagnostics

• Stefania Lettieri,
• Marta d’Amora,
• Adalberto Camisasca,
• Alberto Diaspro and
• Silvia Giordani

Beilstein J. Nanotechnol. 2017, 8, 1878–1888, doi:10.3762/bjnano.8.188

• . They exhibit low density and a high surface area to volume ratio [11][12] and have a spherical shape [13]. Moreover, they can be chemically functionalized, either covalently through chemical reaction [14] (e.g. oxidation [15][16]) or through adsorption of organic molecules by π–π stacking [17]. Our

Self-assembly of chiral fluorescent nanoparticles based on water-soluble L-tryptophan derivatives of p-tert-butylthiacalix[4]arene

• Pavel L. Padnya,
• Irina A. Khripunova,
• Olga A. Mostovaya,
• Timur A. Mukhametzyanov,
• Vladimir G. Evtugyn,
• Vyacheslav V. Vorobev,
• Yuri N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2017, 8, 1825–1835, doi:10.3762/bjnano.8.184

• self-associates not only due to hydrogen bonds, but also due to π–π-stacking and the hydrophobic effects of the chiral amino acid with aromatic fragments [40]. The presence of amide fragments in the structure of the resulting macrocycles also contributes to the formation of aggregates via self

• located at 280 nm for all synthesized compounds (Figure 3B). Such a large Stokes shift for the methyl compounds 8 and 9 (135 nm) is attributed to the formation of excimers. It is known that indole fragments are capable of π–π-stacking, which makes the formation of excimers possible [50][51]. We propose

Three-in-one approach towards efficient organic dye-sensitized solar cells: aggregation suppression, panchromatic absorption and resonance energy transfer

• Jayita Patwari,
• Samim Sardar,
• Bo Liu,
• Peter Lemmens and
• Samir Kumar Pal

Beilstein J. Nanotechnol. 2017, 8, 1705–1713, doi:10.3762/bjnano.8.171

• verified by the sequential one-by-one sensitization of the two dyes where the first layer of the dye is supposed to be acting as the main electron-injecting sensitizer and the second dye layer will prefer to form some π-stacking attachment with the first dye layer as it would not get much vacancy on the

Triptycene-terminated thiolate and selenolate monolayers on Au(111)

• Jinxuan Liu,
• Martin Kind,
• Björn Schüpbach,
• Daniel Käfer,
• Stefanie Winkler,
• Wenhua Zhang,
• Andreas Terfort and
• Christof Wöll

Beilstein J. Nanotechnol. 2017, 8, 892–905, doi:10.3762/bjnano.8.91

• ] thiolates on gold, which exhibit strong π-stacking. More bulky moieties like adamantyl [15][16][17] show noteworthy less attractive intermolecular interactions, which is rather disadvantageous for the formation of well-ordered monolayers. Furthermore, the increased space requirement of the adamantyl moiety

Modeling adsorption of brominated, chlorinated and mixed bromo/chloro-dibenzo-p-dioxins on C₆₀ fullerene using Nano-QSPR

• Piotr Urbaszek,
• Agnieszka Gajewicz,
• Celina Sikorska,
• Maciej Haranczyk and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2017, 8, 752–761, doi:10.3762/bjnano.8.78

• weak dispersion interactions and π−π stacking between – is possible. It is also strongly dependent on the type and amount of halogen substituents. Because the information about experimentally measured dioxin–fullerene sorption tendencies is still very limited [46], further investigation on the sorption

Synthesis of graphene–transition metal oxide hybrid nanoparticles and their application in various fields

• Arpita Jana,
• Elke Scheer and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2017, 8, 688–714, doi:10.3762/bjnano.8.74

• enhanced Li-ion insertion/extraction kinetics in TiO2, especially at high charge/discharge rates [92]. When an inorganic layer has been intercalated between the two graphene layers it prevents the π–π stacking, creating a functional separation between the individual GSs which allows a periodic modulation

Nanoscale isoindigo-carriers: self-assembly and tunable properties

• Tatiana N. Pashirova,
• Andrei V. Bogdanov,
• Lenar I. Musin,
• Julia K. Voronina,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Vladimir F. Mironov,
• Lucia Ya. Zakharova,
• Shamil K. Latypov and
• Oleg G. Sinyashin

Beilstein J. Nanotechnol. 2017, 8, 313–324, doi:10.3762/bjnano.8.34

• work, we focused on the fabrication of nanoscale isoindigo carriers using two approaches: self-assembly and nanoprecipitation. The study aimed to demonstrate the possibility to modulate drug delivery of amphiphilic isoindigo derivatives by tuning hydrophilic–lipophilic balance, π–π stacking interaction

• toxicity as well as to minimize drug degradation and to provide a controllable drug release [51][52][53]. The modification of nanostructures with conjugated π–π fragments leads to the absorption of anticancer drugs via π–π stacking interaction and increases the drug-loading capacity of nanoscale soft

• derivative 2c. This behaviour may be caused by the effect of temperature on hydrogen bonds and/or π-stacking interaction of aggregated 2с. In the case of the long-chain homologue 2h, the increase in temperature exerted little effect on aggregation (Figure S6, Supporting Information File 1). The size of the

Photocatalysis applications of some hybrid polymeric composites incorporating TiO₂ nanoparticles and their combinations with SiO₂/Fe₂O₃

• Andreea Laura Chibac,
• Tinca Buruiana,
• Violeta Melinte and
• Emil C. Buruiana

Beilstein J. Nanotechnol. 2017, 8, 272–286, doi:10.3762/bjnano.8.30

• excellent ability to adsorb aromatic compounds through π–π stacking and other molecular interactions, enhancing the catalysis effect due to the presence of other inorganic components. Also, in the case of the composites with TiO2/Si–O–Si (S2) or TiO2/Fe2O3/Si–O–Si (S4) the presence of a higher number of

Solvent-mediated conductance increase of dodecanethiol-stabilized gold nanoparticle monolayers

• Patrick A. Reissner,
• Jean-Nicolas Tisserant,
• Antoni Sánchez-Ferrer,
• Raffaele Mezzenga and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 2057–2064, doi:10.3762/bjnano.7.196

• molecules do not link pairs of gold nanoparticles. Nevertheless, an increase in conductance upon exchange of alkanethiols with TPT may be expected due to π–π stacking [32]. The immersion in TPT/EtOH following immersion in pure EtOH (Figure 5c) results in almost no increase in device conductance (factor 1.3

A dioxaborine cyanine dye as a photoluminescence probe for sensing carbon nanotubes

• Mohammed Al Araimi,
• Petro Lutsyk,
• Anatoly Verbitsky,
• Yuri Piryatinski,
• Mykola Shandura and
• Aleksey Rozhin

Beilstein J. Nanotechnol. 2016, 7, 1991–1999, doi:10.3762/bjnano.7.190

• SWNTs providing clear evidences of RET from DOB-719 to SWNTs. The new results obtained in these studies allow us to propose the mechanism of interaction between the SWNT and DOB-719, where the dye is attracted to the SWNT surface via π–π stacking with the hydrophobic part while the hydrophilic groups

• energy levels of PL excitation at E22 and emission at E11. In Figure 2b, the three-component system is modelled, where DOB-719 is attached to the SWNT surface via π–π stacking of the hydrophobic parts (π-conjugated frame) while the aqueous medium is faced by the hydrophilic parts (SO3− and COO−). The non

• –astraphloxin [12][19]. Conclusion We have studied the interaction of the organic dye DOB-719 with SWNTs dispersed by an anionic surfactant (SDBS) in water using absorption and PL spectroscopy. We have found that DOB-719 is associated with the SWNTs and forms nano-structured complexes via π–π stacking by the

Graphene-enhanced plasmonic nanohole arrays for environmental sensing in aqueous samples

• Christa Genslein,
• Peter Hausler,
• Eva-Maria Kirchner,
• Rudolf Bierl,
• Antje J. Baeumner and
• Thomas Hirsch

Beilstein J. Nanotechnol. 2016, 7, 1564–1573, doi:10.3762/bjnano.7.150

• binding capacity of the sensor surface. As a simple and environmentally highly relevant model, binding of the plasticizer diethyl phthalate (DEP) via π-stacking was monitored on the rGO gold nanohole array realizing a limit of detection of as low as 20 nM. The concentration-dependent signal change was

• referred to as plasmon–graphene hybrids [37]. On the other hand, interactions of molecules with aromatic systems via π-stacking is strongly promoted by the sp2-hybridized carbon atoms arranged in a honeycomb structure. In this study a sensor for diethyl phthalate as model analyte was developed. It is known

• that this type of plasticizers adsorbs on polystyrene resins by multiple adsorbent–adsorbate interactions such as hydrogen bonding and π-stacking [38], which makes them an ideal analyte for the evaluation of the graphene-modified gold surfaces in SPR. Nanostructured surfaces are promising in enhancing

Photocurrent generation in carbon nanotube/cubic-phase HfO₂ nanoparticle hybrid nanocomposites

• Protima Rauwel,
• Augustinas Galeckas,
• Martin Salumaa,
• Frédérique Ducroquet and
• Erwan Rauwel

Beilstein J. Nanotechnol. 2016, 7, 1075–1085, doi:10.3762/bjnano.7.101

• surface of the nanoparticles on forming esters [25]. Moreover, π–π stacking has also proven effective in attaching inorganic metal oxide nanoparticles to the surface of nonfunctionalized nanotubes. In this approach, the aromatic ring of the CNT is directly connected to the benzyl ring of the inorganic

Phenalenyl-based mononuclear dysprosium complexes

• Yanhua Lan,
• Andrea Magri,
• Olaf Fuhr and
• Mario Ruben

Beilstein J. Nanotechnol. 2016, 7, 995–1009, doi:10.3762/bjnano.7.92

• between O6H6 and O5 (1.90 Å) associated with the non-depronated phenalenyl, and an intermolecular hydrogen bond between O7H7 and Cl1 (2.49 Å) involving EtOH. Clearly, the intermolecular hydrogen bonds, together with the π–π stacking (ca. 3.45 Å) between the phenalenyl moieties, aid the molecular packing

• hydrogen bonds packs the molecules together and drives the co-crystallization. Additionally, weak π–π stacking (ca. 3.61 Å) between the phenalenyl moieties of 2a and 2b might be also responsible for the co-crystallization of the complexes in one asymmetric unit. Compound [Dy(PLN)3(H2O)2]·H2O (3

• Supporting Information File 1). As mentioned in the structural description, this molecule is rich of hydrogen bonding and the π–π stacking. With such a narrow torsion angle calculated from Magellan, one can think that the two magnetic centers could be strongly interacting through the π orbitals of the

Optical absorption signature of a self-assembled dye monolayer on graphene

• Tessnim Sghaier,
• Sylvain Le Liepvre,
• Céline Fiorini,
• Ludovic Douillard and
• Fabrice Charra

Beilstein J. Nanotechnol. 2016, 7, 862–868, doi:10.3762/bjnano.7.78

• the environment [40] compared with the isolated molecules in toluene solution could explain a large red-shift. Electronic interactions between conjugated π-electron systems of molecule and graphene (π-stacking), as evidenced by STM spectroscopy for non-alkylated PTCDI [28], may also play a role in

High-resolution noncontact AFM and Kelvin probe force microscopy investigations of self-assembled photovoltaic donor–acceptor dyads

• Benjamin Grévin,
• Pierre-Olivier Schwartz,
• Laure Biniek,
• Martin Brinkmann,
• Nicolas Leclerc,
• Elena Zaborova and
• Stéphane Méry

Beilstein J. Nanotechnol. 2016, 7, 799–808, doi:10.3762/bjnano.7.71

• with respect to the substrate are evidenced. They correspond to (i) edge-on co-oligomer orientation (π-stacking direction in the substrate plane) and (ii) face-on co-oligomer orientation with the π-stacking direction normal to the substrate. Both these molecular orientations coexist in the standing

• . These defects impact the molecular dipoles at the surface of the film, due to the mutual polarization effects and wave function overlap with the recessed layers. Especially, the top layers may cover recessed edge-on stacks displaying a different π-stacking direction, or eventually sub-surface flat-on

• domains. The first hypothesis is particularly supported by the existence of cross-hatch patterns in the TEM images (Figure 6b), clearly revealing that lamellae with different π-stacking directions overlap in some parts of the film. The TEM bright field images correspond to 2D projections of a 3D film

Assembling semiconducting molecules by covalent attachment to a lamellar crystalline polymer substrate

• Rainhard Machatschek,
• Patrick Ortmann,
• Renate Reiter,
• Stefan Mecking and
• Günter Reiter

Beilstein J. Nanotechnol. 2016, 7, 784–798, doi:10.3762/bjnano.7.70

• emission. In addition, upon π–π stacking of molecule 1, fluorescence emission exhibits large spectral shifts [23]. Therefore, we can draw conclusions about the packing density of semiconducting molecule 1 attached to CPE45 nanocrystal surfaces without having to resort to conductivity measurements. As a

• observed by AFM. However, after longer grafting times (e.g., after three days) islands of 1 molecules formed percolating pathways on the crystal surface. We note that the π–π stacking energy of perylene molecules is rather high [25], consistent with a high melting point and poor solubility of the resulting

• crystalline aggregates. Hence, crystalline islands of semiconducting 1 molecules are expected to grow preferentially along the π–π stacking direction of the perylene molecules [33][34]. Accordingly, during grafting, incoming molecules were probably guided by the ones already present at the lateral crystal

Comparison of the interactions of daunorubicin in a free form and attached to single-walled carbon nanotubes with model lipid membranes

• Dorota Matyszewska

Beilstein J. Nanotechnol. 2016, 7, 524–532, doi:10.3762/bjnano.7.46

• two main methods of attaching the drugs comprise either covalent attachment or physical adsorption based on π–π stacking interactions. There are a few reports in the literature on the preparation and characterization of CNTs-DNR adducts used as drug delivery systems. In those works daunorubicin was

Light-powered, artificial molecular pumps: a minimalistic approach

• Giulio Ragazzon,
• Massimo Baroncini,
• Serena Silvi,
• Margherita Venturi and
• Alberto Credi

Beilstein J. Nanotechnol. 2015, 6, 2096–2104, doi:10.3762/bjnano.6.214

• exploiting the different ability of the trans- and cis-azobenzene units to interact with the naphthalene moieties by π-stacking. Finally, in order to enhance the ring–axle interactions, dichloromethane was used as the solvent in the place of acetonitrile. Indeed, spectrophotometric and fluorimetric

Electrospray deposition of organic molecules on bulk insulator surfaces

• Antoine Hinaut,
• Rémy Pawlak,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2015, 6, 1927–1934, doi:10.3762/bjnano.6.195

• stabilization can be explained by a dominant molecule–molecule interaction by π–π-stacking [29][37][44][45]. Due to the symmetric arrangement of the two 3-cyanophenyl groups the electrostatic binding to the surface is only small and the molecular wires might easily flip or rearrange explaining the low stability

• characterized theses islands showing molecular assemblies stabilized by π–π stacking organization and anchoring through the cyano group of the molecules and K+ ions of the surface. To achieve single molecule deposition, we added a pumping chamber in the setup that lowered the number of molecules reaching the

Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum

• Andrea Candini,
• Nils Richter,
• Domenica Convertino,
• Camilla Coletti,
• Franck Balestro,
• Wolfgang Wernsdorfer,
• Mathias Kläui and
• Marco Affronte

Beilstein J. Nanotechnol. 2015, 6, 711–719, doi:10.3762/bjnano.6.72

• assure a high mechanical stability even above room temperature. Finally, the possibility to exploit specific functionalizations to attach the molecular units to the graphene electrodes through carbon bonds and/or π-stacking seems to be a promising route to develop well-defined and robust junction

Self-assembled anchor layers/polysaccharide coatings on titanium surfaces: a study of functionalization and stability

• Ognen Pop-Georgievski,
• Dana Kubies,
• Josef Zemek,
• Neda Neykova,
• Roman Demianchuk,
• Eliška Mázl Chánová,
• Miroslav Šlouf,
• Milan Houska and
• František Rypáček

Beilstein J. Nanotechnol. 2015, 6, 617–631, doi:10.3762/bjnano.6.63

• PDA units can establish a wide range of non-covalent bonds through π stacking, hydrogen bonding, and van der Waals- and hydrophobic-interactions. PDA films have been used as the anchor layers of non-fouling polymer brushes [32][33][34], substrates for cell adhesion [35][36] and as platforms for

Electrical response of liquid crystal cells doped with multi-walled carbon nanotubes

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2015, 6, 396–403, doi:10.3762/bjnano.6.39

• they are currently under study. The nanotubes contain charges and ionic impurities that could contribute to the MWCNT reorientation with applied field, but do not contribute to the eventual relaxation. A second cause that could contribute to the effect is the π–π stacking between CNTs and LC molecules

Release behaviour and toxicity evaluation of levodopa from carboxylated single-walled carbon nanotubes

• Julia M. Tan,
• Jhi Biau Foo,
• Sharida Fakurazi and
• Mohd Zobir Hussein

Beilstein J. Nanotechnol. 2015, 6, 243–253, doi:10.3762/bjnano.6.23

• materials characterization methods including Fourier transform infrared spectroscopy, Raman spectroscopy, elemental analysis, UV–vis spectroscopy and scanning electron microscopy. The results showed that SWCNT–COOH were able to form supramolecular complexes with LD via a π–π stacking interaction and

• two major paths for noncovalent π-stacking interactions involving aromatic rings to occur: sandwich and parallel-displaced. Sandwich is a π-stacking geometry that occurs between the benzene groups through electrostatic repulsion, whereas the electrostatic interaction between the benzenes will result

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• , good conductivity, recyclability, and the high dielectric constant of ionic liquids induce the exfoliation of graphite by weakening the π–π stacking interactions. Indeed, the use of ionic liquids is considered a highly versatile and industrially scalable method for the preparation of graphene