Anchoring of a dye precursor on NiO(001) studied by non-contact atomic force microscopy

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2018, 9, 242–249, doi:10.3762/bjnano.9.26

• sensitizing NiO surfaces for an optimized photon absorption is an on-surface dye synthesis, which has earlier been termed the “surfaces-as-ligands” approach [42]. The first ligand is designed to anchor to the surface through groups such as carboxylic or phosphonic acids and has a metal-binding domain such as

Gas-assisted silver deposition with a focused electron beam

• Luisa Berger,
• Katarzyna Madajska,
• Iwona B. Szymanska,
• Katja Höflich,
• Mikhail N. Polyakov,
• Jakub Jurczyk,
• Carlos Guerra-Nuñez and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 224–232, doi:10.3762/bjnano.9.24

• organic precursors are introduced with a gas injection system (GIS) and physisorb onto the substrate. The electrons induce local precursor dissociation on the surface, which in the ideal case results in a selective and pure metal deposit and volatile organic ligands. However, the organic ligand elements

• interaction into deposited metal atoms and volatile, yet still physisorbed ligands. Due to the high electron flux within the PE beam area, the desorption rate of these volatile ligands is lower than their dissociation rate, resulting in a higher carbon content. Outside the PE beam area, the adsorbates still

• dissociate by electron impact into deposited metal atoms and volatile physisorbed ligands. Yet the desorption rate of the ligands is larger than their further dissociation by the much lower electron flux, preventing co-deposition and leading to purer silver deposits. Due to writing in multiple passes, the

Comparative study of post-growth annealing of Cu(hfac)₂, Co₂(CO)₈ and Me₂Au(acac) metal precursors deposited by FEBID

• Marcos V. Puydinger dos Santos,
• Aleksandra Szkudlarek,
• Artur Rydosz,
• Carlos Guerra-Nuñez,
• Fanny Béron,
• Kleber R. Pirota,
• Stanislav Moshkalev,
• José Alexandre Diniz and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 91–101, doi:10.3762/bjnano.9.11

• capable of defining 3-dimensional metal deposits at nanometre scale for above applications. However, codeposition of organic ligands when using organometallic precursors is a typical problem that limits FEBID of pure metal nanostructures. In this work, we present a comparative study using a post-growth

• (up to 95 atom % relative to carbon) were obtained by means of impact-enhanced desorption of residual organic ligands using a supersonic argon carrier gas jet to deliver the organometallic precursor [45]. Other works suggest the autocatalytic deposition of carbonyls, such as Fe(CO)5 [46][47] and Co2

Electron-driven and thermal chemistry during water-assisted purification of platinum nanomaterials generated by electron beam induced deposition

• Ziyan Warneke,
• Markus Rohdenburg,
• Jonas Warneke,
• Janina Kopyra and
• Petra Swiderek

Beilstein J. Nanotechnol. 2018, 9, 77–90, doi:10.3762/bjnano.9.10

• desired solid material and organic ligands that enhance their volatility. Metal organic precursors are thus used to fabricate metallic deposits. In the ideal case, a pure metal should remain at the surface while the organic ligands decompose into volatile products that are pumped away. However, this is

• usually not the case and material from the ligands tends to be incorporated in the deposit and thus deteriorates its physical properties [1][9][10][11]. Trimethyl(methylcyclopentadienyl)platinum(IV) (MeCpPtMe3, Figure 1a) is widely applied as precursor for deposition of Pt because of its very favourable

• with equally small contributions of ethane (C2H6) according to a mass spectrum recorded during the initial stages of electron exposure (Supporting Information File 1, Figure S2). The very small quantity of C2H6, confirms again the previous conclusion [10] that recombination of CH3 ligands dissociating

Response under low-energy electron irradiation of a thin film of a potential copper precursor for focused electron beam induced deposition (FEBID)

• Leo Sala,
• Iwona B. Szymańska,
• Céline Dablemont,
• Anne Lafosse and
• Lionel Amiaud

Beilstein J. Nanotechnol. 2018, 9, 57–65, doi:10.3762/bjnano.9.8

• ligands that are solid and stable under ambient conditions. They are directly deposited on the surface for studying the fragmentation with surface science tools. Results: Infrared spectroscopy and high-resolution electron energy loss spectroscopy (HREELS) are combined to show that the precursor is able to

• spontaneously lose amine ligands under vacuum. This loss can be enhanced by mild heating. The combination of mass spectrometry and low-energy electron irradiation (0–15 eV) shows that full amine ligands can be released upon irradiation, and that fragmentation of the perfluorinated ligands is induced by

• electrons of energy as low as 1.5 eV. Finally, the cross section for this process is estimated from the temporal evolution in the experiments on electron-stimulated desorption (ESD). Conclusion: The release of full ligands under high vacuum and by electron irradiation, and the cross section measured here

Impact of titanium dioxide nanoparticles on purification and contamination of nematic liquid crystals

• Dmitrii Pavlovich Shcherbinin and
• Elena A. Konshina

Beilstein J. Nanotechnol. 2017, 8, 2766–2770, doi:10.3762/bjnano.8.275

• by plasma synthesis and were not covered with any ligands. Dry NPs were added to LCs at a concentration of 0.25, 0.5 and 1 wt %. The composites were prepared in isotropic phase over one hour by ultrasonication. To estimate ion density (c) and average diffusion coefficient (D) in LC1, LC2 and their

The rational design of a Au(I) precursor for focused electron beam induced deposition

• Ali Marashdeh,
• Thiadrik Tiesma,
• Niels J. C. van Velzen,
• Sjoerd Harder,
• Remco W. A. Havenith,
• Jeff T. M. De Hosson and
• Willem F. van Dorp

Beilstein J. Nanotechnol. 2017, 8, 2753–2765, doi:10.3762/bjnano.8.274

• ], they are often inefficient in removing the ligands that are currently used to make the precursor molecules volatile [28][29][30]. The decomposition of the precursor is then incomplete, leaving large parts of the ligand structure on the surface. This leads to for instance low metal content and poor

• sufficiently reactive to yield the desired reaction product in a single step, but not so reactive that it dissociates unselectively or has a short shelf life. It has already been determined that electrons cannot remove large ligands. Examples are the cyclopentadienyl ligand in trimethyl(methylcyclopentadienyl

• several questions. How do the ligands determine stability, shelf life and volatility? What is the origin of the short lifetime of ClAuCO in vacuum? Why is MeAuPMe3 volatile, while ClAuPMe3 is not? And can we, based on the results we have, come to a rational design of a Au precursor with the desired

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

• . They can be combined with polymers to form conductive composites and have been used as the basis of molecular electronic devices. This review summarizes the multidimensional role of surface ligands that cover their metal cores. Ligands not only passivate crystal facets and determine growth rates and

• shapes; they also affect size and colloidal stability. Particle shapes can be tuned via the ligand choice while ligand length, size, ω-functionalities, and chemical nature influence shelf-life and stability of nanoparticles in dispersions. When particles are deposited, ligands affect the electrical

• properties of the resulting film, the morphology of particle films, and the nature of the interfaces. The effects of the ligands on sintering, cross-linking, and self-assembly of particles in electronic materials are discussed. Keywords: conductivity; inks; layers; ligands; nanoparticles; Introduction

Synthesis of [{AgO₂CCH₂OMe(PPh₃)}_n] and theoretical study of its use in focused electron beam induced deposition

• Jelena Tamuliene,
• Julian Noll,
• Peter Frenzel,
• Tobias Rüffer,
• Alexander Jakob,
• Bernhard Walfort and
• Heinrich Lang

Beilstein J. Nanotechnol. 2017, 8, 2615–2624, doi:10.3762/bjnano.8.262

• coordination polymer in the solid state as evidenced by single crystal X-ray structure analysis. The coordination geometry at Ag+ is of the [3 + 1] type, whereby the carboxylate anions act as bridging ligands. The formation of PPh3–Ag(I) coordinative bonds results in distorted T-shaped AgPO2 units, which are

• ). Thereby, the carboxylate anions act as µ-bridging ligands to link two adjacent silver(I) ions. Due to the coordination of a PPh3 group to Ag(I), virtually planar AgPO2 coordination units are observed. Planarity is revealed by the calculation of a mean plane. The average deviation from planarity amounts to

Localized growth of carbon nanotubes via lithographic fabrication of metallic deposits

• Fan Tu,
• Martin Drost,
• Imre Szenti,
• Janos Kiss,
• Zoltan Kónya and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2017, 8, 2592–2605, doi:10.3762/bjnano.8.260

• CNT yield [21]. The existence of the corresponding carbon contamination was traced back to deposits from the residual gas in the high-vacuum (HV) environment and the dissociation of the carbon-containing precursor ligands [19]. With our “surface science approach” to FEBIP, that is, working in an ultra

Interactions of low-energy electrons with the FEBID precursor chromium hexacarbonyl (Cr(CO)₆)

• Jusuf M. Khreis,
• João Ameixa,
• Filipe Ferreira da Silva and
• Stephan Denifl

Beilstein J. Nanotechnol. 2017, 8, 2583–2590, doi:10.3762/bjnano.8.258

• further irradiated by a high-energy electron beam. The electron beam decomposes the precursor molecules, leaving the metal on the surface and the organic ligands are pumped away [2][3]. FEBID has shown high potential in growing defined three-dimensional structures close to any geometry and to write on

• uneven surfaces. Although FEBID is a promising technique, improvements are still needed in order to get pure and highly resolved deposits. CVD precursors are normally used as FEBID precursors; however, their performance is limited, leading to co-deposition of ligands and ligand fragments together with

• well as to minimise the adverse or unwanted effects, such as non-pure metal deposition resulting from the co-deposition of ligands. In order to improve the quality of metallic deposits, LEE interactions with organometallic precursors have been studied. Several studies have been reported, e.g., DEA

Direct writing of gold nanostructures with an electron beam: On the way to pure nanostructures by combining optimized deposition with oxygen-plasma treatment

• Domagoj Belić,
• Mostafa M. Shawrav,
• Emmerich Bertagnolli and
• Heinz D. Wanzenboeck

Beilstein J. Nanotechnol. 2017, 8, 2530–2543, doi:10.3762/bjnano.8.253

• is essential for successful binding of ligands, such as thiols [80]. From that point of view, our cleaning procedure presents a valuable approach for experimental realization of structurally sound, precisely patterned nanostructures of a high Au content, with exposed Au surfaces available for

Strategy to discover full-length amyloid-beta peptide ligands using high-efficiency microarray technology

• Clelia Galati,
• Natalia Spinella,
• Lucio Renna,
• Danilo Milardi,
• Francesco Attanasio,
• Michele Francesco Maria Sciacca and
• Corrado Bongiorno

Beilstein J. Nanotechnol. 2017, 8, 2446–2453, doi:10.3762/bjnano.8.243

• immobilize the peptide at the silicon surface. The same behavior can be assumed for shorter peptides. Test of amyloid-beta 1–40 binding by peptide ligands on HES The synthesized pentapeptide KLVFF and a commercial therapeutic heptapeptide, Semax, have been assayed to investigate their ability to bind full

• bind full-length Aβ and to prevent its fibrillation [30]. Semax was chosen for its different behavior (as will be discussed below). The peptides were tested, as amyloid ligands, using the Cy3-labeled Aβ40 conjugate for fluorescence detection. As expected, after the immobilization of the unlabeled

Comparing postdeposition reactions of electrons and radicals with Pt nanostructures created by focused electron beam induced deposition

• Julie A. Spencer,
• Michael Barclay,
• Miranda J. Gallagher,
• Robert Winkler,
• Ilyas Unlu,
• Yung-Chien Wu,
• Harald Plank,
• Lisa McElwee-White and
• D. Howard Fairbrother

Beilstein J. Nanotechnol. 2017, 8, 2410–2424, doi:10.3762/bjnano.8.240

• postdeposition purification strategies capable of removing halogen atoms, despite the presence of halide ligands in many organometallic precursors. Compared to carbon, contaminant halogen atoms in FEBID structures present a different challenge when it comes to purification strategies as they cannot be removed by

• etch substrates or equipment. The use of electrons was motivated in part by previous ultrahigh vacuum (UHV) surface science studies which showed that for 1–2 monolayer (ML) thin films of organometallic precursors with halide ligands, the halogens can be removed [29][31]. The importance of halogen

Electron beam induced deposition of silacyclohexane and dichlorosilacyclohexane: the role of dissociative ionization and dissociative electron attachment in the deposition process

• Ragesh Kumar T P,
• Sangeetha Hari,
• Krishna K Damodaran,
• Oddur Ingólfsson and
• Cornelis W. Hagen

Beilstein J. Nanotechnol. 2017, 8, 2376–2388, doi:10.3762/bjnano.8.237

• eV [50]) has proven to increase molecular fragmentation through DEA considerably [51][52]. Combined with perfluorination of ligands to increase the attachment cross sections at threshold, this could be a viable approach to probe the relevance of DEA by very low energy (0+ eV) SEs produced by the

Tailoring the nanoscale morphology of HKUST-1 thin films via codeposition and seeded growth

• Landon J. Brower,
• Lauren K. Gentry,
• Amanda L. Napier and
• Mary E. Anderson

Beilstein J. Nanotechnol. 2017, 8, 2307–2314, doi:10.3762/bjnano.8.230

• -organic frameworks (MOFs), composed of both metal ions and organic ligands, represent a class of extremely porous, crystalline materials with high surface area. Research has investigated their integration as thin films, namely surface-anchored metal-organic frameworks (surMOFs), into a wide variety of

Dissociative electron attachment to coordination complexes of chromium: chromium(0) hexacarbonyl and benzene-chromium(0) tricarbonyl

• Janina Kopyra,
• Paulina Maciejewska and
• Jelena Maljković

Beilstein J. Nanotechnol. 2017, 8, 2257–2263, doi:10.3762/bjnano.8.225

• ]− channel is visible via two overlapping resonant structures appearing in the energy range below 1.5 eV with a dominant structure peaking at around 0 eV. The peak maxima of the fragments generated by the loss of two or three CO ligands are blue-shifted and the most intense peaks within the ion yield curves

• homoleptic Cr(CO)6. Besides, we have observed the formation of anions due to the loss of C6H6 and one or more CO units. Finally, we found that Cr−, when stripped of all ligands, is generated through a high-energy resonance, peaking at 8 eV. Keywords: benzene-chromium(0) tricarbonyl; chromium(0) hexacarbonyl

• ]), bidentate (e.g., hexafluoroacetylacetone [17]), and mixed ligands (e.g., nitrosyl and carbonyl [9][10], methyl and methylcyclopentadienyl [18], π-allyl, carbonyl, bromide [19]). These studies cover both the fragmentation patterns and kinetics of electron attachment processes. It appears that for carbonyl

The interplay between spin densities and magnetic superexchange interactions: case studies of mono- and trinuclear bis(oxamato)-type complexes

• Azar Aliabadi,
• Bernd Büchner,
• Vladislav Kataev and
• Tobias Rüffer

Beilstein J. Nanotechnol. 2017, 8, 2245–2256, doi:10.3762/bjnano.8.224

• . Therefore protons probably also contribute to the line in the EDNMR spectra around 50 MHz. Like the ENDOR results, the obtained HF tensors indicate two different groups of N ligands classified as groups A and B for 8. The same observation is obtained for 10 as well. The 14N HF constants for group A are

• coupling constants for a complex containing a Cu(II) ion surrounded by four ligands in a square planar configuration are derived and expressed as: In these expressions, Pκ is the Fermi contact term with P(63Cu) = μBgeμnγ·3d = 1164 MHz, that is, the dipolar HF coupling parameter of the unpaired electron

• limitation of the model by Morton and Preston [49] is that it presumes calculation of the HF constants for a free atom. With this in mind, it is indeed reasonable to conclude that the transfer of the spin density from the metal ions to the bonding ligands is certainly an important but not yet the decisive

Au₅₅, a stable glassy cluster: results of ab initio calculations

• Dieter Vollath,
• David Holec and
• Franz Dieter Fischer

Beilstein J. Nanotechnol. 2017, 8, 2221–2229, doi:10.3762/bjnano.8.222

• ][2][3][4][5][6], the Au55 cluster has been used as model for a small cluster with a magic number of atoms. Their experimental work, and in particular the structural analysis, were possible only by attaching organic ligands to the cluster surface, in order to prevent the clusters from coagulating

• immediately to larger particles [3]. Without any doubt, the thus obtained structural details do, to some extent, depend on the type of the ligands [4]; however, the structure is not influenced fundamentally. An important result of Schmid’s work is the description of the structure of Au55 as a sequence of two

• shells [1][4]. On average, these clusters are composed of 13 atoms in the center and 42 atoms in the outer shell. From the atoms in the outer shell, 18 atoms are bond to the ligands [1]. Furthermore, these shells show a very broad scattering of the coordination numbers [4]. This fact was taken as an

Suppression of low-energy dissociative electron attachment in Fe(CO)₅ upon clustering

• Jozef Lengyel,
• Peter Papp,
• Štefan Matejčík,
• Jaroslav Kočišek,
• Michal Fárník and
• Juraj Fedor

Beilstein J. Nanotechnol. 2017, 8, 2200–2207, doi:10.3762/bjnano.8.219

• , isotope distributions and high-energy resolution ion yields can be obtained. Results The mass spectrometry analysis of anions resulting from electron interactions with Fe(CO)5 clusters is complicated by the fact that two CO ligands have the same mass as one iron atom (56 amu). We have used the fact that

• intact monomer units attached to it. The CLUB data for pure Fe(CO)5 clusters and for Fe(CO)5 aggregates adsorbed on large Ar nanoparticles are very similar, with one notable difference: with the decreasing number of ligands in the fragment anion, the band between 5 and 10 eV disappears when the

• forces difficult to asses. For aggregates on argon nanoparticles, the band between 5 and 10 eV is clearly disappearing with the increasing number of removed ligands. It is thus most probably linked with the number of ligands removed in the step (Equation 6). The origin of the ligand stabilization by

Systematic control of α-Fe₂O₃ crystal growth direction for improved electrochemical performance of lithium-ion battery anodes

• Nan Shen,
• Miriam Keppeler,
• Barbara Stiaszny,
• Holger Hain,
• Filippo Maglia and
• Madhavi Srinivasan

Beilstein J. Nanotechnol. 2017, 8, 2032–2044, doi:10.3762/bjnano.8.204

• verified by results of our test series. Diamines are typical chelate ligands that interact with appropriate coordination centers. First, octahedral-shaped complexes are formed [29], formally described as (Fe[C2H2N2R1R2]3)3+. Diamine derivatives, in which the two amine groups are located at adjacent C atoms

• −. This will result in the gradual loss of diamine ligands, leading to complexes with two OH− groups and two diamines that form a quasi-square-plane perpendicular to the OH− direction [29]. Therefore, the following hydrolysis process is inhibited in the planar direction, but favored in the normal

Synthesis and functionalization of NaGdF₄:Yb,Er@NaGdF₄ core–shell nanoparticles for possible application as multimodal contrast agents

• Dovile Baziulyte-Paulaviciene,
• Vitalijus Karabanovas,
• Marius Stasys,
• Greta Jarockyte,
• Vilius Poderys,
• Simas Sakirzanovas and
• Ricardas Rotomskis

Beilstein J. Nanotechnol. 2017, 8, 1815–1824, doi:10.3762/bjnano.8.183

• structure, where the nonactive shell protects the luminescent rare earth ions in the core from quenching caused by surface defects and organic ligands [10]. A wide variety of studies were performed to synthesize dual functional core–shell UCNPs [11][12][13]. However, it remains difficult to obtain hexagonal

• phase and stabilized with hydrophobic ligands, such as oleic acid. Consequently, they can only be dispersed in nonpolar solvents (e.g., toluene, cyclohexane). In the past few years, several methods including surface silanization [14], ligand exchange [15], ligand oxidation [16], ligand removal [17], and

• 80. The presence of the Tween 80 coating was verified by comparing its FTIR spectra to that of pure oleic acid, oleate ligands coated particles, pure Tween 80, and the final coated nanoparticles (Figure 3). NaGdF4:Yb,Er UCNPs prepared in the presence of oleic acid shows characteristic absorption

Methionine-mediated synthesis of magnetic nanoparticles and functionalization with gold quantum dots for theranostic applications

• Arūnas Jagminas,
• Agnė Mikalauskaitė,
• Vitalijus Karabanovas and
• Jūrate Vaičiūnienė

Beilstein J. Nanotechnol. 2017, 8, 1734–1741, doi:10.3762/bjnano.8.174

• specific targeting ligands, such as aptamers and antibodies. This synthesis way may also be explored in future to design superparamagnetic, methionine-stabilized plasmonic magnetite NPs decorated with Au0/Au+1 QDs. Experimental Chemicals: All chemicals, including Co(II) and Fe(III) chlorides, and HAuCl4

Group-13 and group-15 doping of germanane

• Nicholas D. Cultrara,
• Maxx Q. Arguilla,
• Shishi Jiang,
• Chuanchuan Sun,
• Michael R. Scudder,
• R. Dominic Ross and
• Joshua E. Goldberger

Beilstein J. Nanotechnol. 2017, 8, 1642–1648, doi:10.3762/bjnano.8.164

• optoelectronic properties via covalent modification with surface ligands [3][24][25][26][27][28]. While the electron mobility of germanane at room temperature has been predicted to be greater than 18,000 cm2·V−1·s−1, transport measurements on non-extrinsically doped crystals were highly resistive, indicating the

Deposition of exchange-coupled dinickel complexes on gold substrates utilizing ambidentate mercapto-carboxylato ligands

• Martin Börner,
• Laura Blömer,
• Marcus Kischel,
• Peter Richter,
• Georgeta Salvan,
• Dietrich R. T. Zahn,
• Pablo F. Siles,
• Maria E. N. Fuentes,
• Carlos C. B. Bufon,
• Daniel Grimm,
• Oliver G. Schmidt,
• Daniel Breite,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Nanotechnol. 2017, 8, 1375–1387, doi:10.3762/bjnano.8.139

• ) and 8 (J = +20.8 cm−1; H = −2JS1S2). The reactivity of complexes 6–8 is reminiscent of that of pure thiolato ligands, which readily chemisorb on Au surfaces as verified by contact angle, atomic force microscopy (AFM) and spectroscopic ellipsometry measurements. The large [Ni2L] tail groups, however

• , prevent the packing and self-assembly of the hydrocarbon chains. The smaller film thickness of 7 is attributed to the specific coordination mode of the coligand. Results of preliminary transport measurements utilizing rolled-up devices are also reported. Keywords: ambidentate ligands; chemisorption; gold

• macrocyclic complexes have not been anchored to gold via ambidentate mercaptobenzoate ligands. However, polynuclear Mn12 complexes have been fixed to gold via perfluorinated mercaptobenzoate linkers [42]. Results and Discussion Synthesis and characterization of complexes The investigated compounds and their