Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules

• Sabine Maier and
• Meike Stöhr

Beilstein J. Nanotechnol. 2021, 12, 950–956, doi:10.3762/bjnano.12.71

• from the substrates [73]. Suitable functionalization of molecules is another concept to vary their adsorption strength on metal substrates. For instance, partial fluorination of pentacene molecules decreased the adsorption strength on strongly interacting substrates such as Cu [74] but did not result

• in notable effects on Ag(111) [75]. Although this decoupling concept is only practical on Cu, the fluorination significantly changed the molecular multilayer growth on Ag(111) and led to a physical decoupling with a nearly bulk crystalline structure for the fluorinated pentacene. Two articles within

Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• properties. Hence, TMPcs are well suited for systematic studies of interface properties. The fluorination of TMPcs varies exceptionally the ionization potential (IP), affecting distinctly the interface properties [29][30][31][32]. As recently shown for FePcFx/MoS2 [33], a charge transfer at interfaces might

• be driven by the ionization potential difference between substrate and adsorbate. In addition, fluorination may affect significantly the adsorption geometry on surfaces as well as the single-crystal structure and arrangement in thin films [34][35][36][37]. Furthermore, local chemical interactions

• strength of the interface interaction depends on the particular adsorption site. The question arises whether or not the interaction is further affected by the fluorination of the CoPc molecule. C 1s, F 1s and Co 2p3/2 core level spectra of CoPcF16 on STO are shown in Figure 4. The peak fit data are given

Impact of fluorination on interface energetics and growth of pentacene on Ag(111)

• Qi Wang,
• Meng-Ting Chen,
• Antoni Franco-Cañellas,
• Bin Shen,
• Thomas Geiger,
• Holger F. Bettinger,
• Frank Schreiber,
• Ingo Salzmann,
• Alexander Gerlach and
• Steffen Duhm

Beilstein J. Nanotechnol. 2020, 11, 1361–1370, doi:10.3762/bjnano.11.120

• . Keywords: decoupling; fluorination; metal–organic interfaces; organic pi-conjugated molecules; X-ray standing wave technique; Introduction The performance of organic (opto)electronic devices is strongly affected by the energy level alignment at the various interfaces in such devices [1][2][3

• ]. Fluorination is a viable way to change the ionization energies (IEs) of organic semiconductor thin films [4][5][6], which are an important parameter for energy level alignment [7][8]. Moreover, at organic–metal interfaces, fluorination is believed to decrease the coupling strength between the substrate and the

• adsorbate [9][10][11]. However, at such interfaces, vertical adsorption heights [12][13], interface dipoles (vacuum level shifts) [9][14] and consequently the energy level alignment [15][16][17] are affected by fluorination. Furthermore, fluorination can change the molecular multilayer growth [18][19][20

Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions

• Da Shi,
• Justine Wallyn,
• Dinh-Vu Nguyen,
• Francis Perton,
• Delphine Felder-Flesch,
• Sylvie Bégin-Colin,
• Mounir Maaloum and
• Marie Pierre Krafft

Beilstein J. Nanotechnol. 2019, 10, 2103–2115, doi:10.3762/bjnano.10.205

• -life of the corresponding bubbles, was also significantly higher than for those prepared with non-fluorinated NPs and, at least for C2F5OEG8Den (6.1 ± 0.9 h), comparable to that of DPPC (6.8 ± 0.5 h; Table 2 and Figure 7). These differences in behavior that depend on the fluorination of the dendron

Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• atoms, it is possible to controllably tune the concentration of oxygen vacancies by modifying the site potential of O2 and O3 through, e.g., fluorination or sulfidation of Bi2WO6. Conclusion In summary, we have synthesized Bi2WO6 nanoflakes of 6–10 nm in thickness by using a solvothermal method, and

• to controllably tune the concentration of oxygen vacancies by modifying the site potential of O2 and O3 atoms via fluorination or sulfidation. Experimental Solvothermal synthesis Bi2WO6 nanoflakes were synthesized by a solvothermal method. All chemical reagents were of analytical purity. Into 60 mL

Impact of the anodization time on the photocatalytic activity of TiO₂ nanotubes

• Jesús A. Díaz-Real,
• Geyla C. Dubed-Bandomo,
• Juan Galindo-de-la-Rosa,
• Luis G. Arriaga,
• Janet Ledesma-García and
• Nicolas Alonso-Vante

Beilstein J. Nanotechnol. 2018, 9, 2628–2643, doi:10.3762/bjnano.9.244

• supports the idea of a fluorination. The proposed reaction process is ≡Ti–OH + F− → ≡Ti–F + OH− occurring through an inner-sphere ligand substitution reaction with hydroxy groups [30]. The F 1s spectra show an asymmetrical shape, arising from different interactions of the F atoms, with a major peak at a

• the TNTs does not correspond directly to their length, but more to the amount of surface hydroxy groups (induced by the fluorination and N dopant atoms) observed by XPS, which is related to the anchoring process. Thus, while the total exposed area (inner or outer walls of the tubes) remains important

• of surface hydroxy groups induced by the fluorination of the TNTs. Experimental Preparation of TiO2-NT electrodes TiO2 nanotubes were fabricated by electrochemical anodic oxidation of Ti foils (99% purity, 0.127 mm, Alfa-Aesar) [93]. Briefly, the foils were pre-treated with sandpaper, #600, #1200 and

Fluorination of vertically aligned carbon nanotubes: from CF₄ plasma chemistry to surface functionalization

• Claudia Struzzi,
• Mattia Scardamaglia,
• Jean-François Colomer,
• Alberto Verdini,
• Luca Floreano,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2017, 8, 1723–1733, doi:10.3762/bjnano.8.173

• obtained via FTIR and mass spectrometry are combined with the XPS and Raman analysis of the sample surface showing the dependence on different plasma parameters (power, time and distance from the plasma region) on the resulting fluorination. Photoemission and absorption spectroscopies are used to

• investigate the evolution of the electronic properties as a function of the fluorine content at the vCNT surface. The samples suffer a limited ageing effect, with a small loss of fluorine functionalities after two weeks in ambient conditions. Keywords: carbon nanotubes; CF4 plasma; fluorination; plasma

• nanotubes [18][19][20][21]. This carbon allotrope exhibits a low-reactive surface; therefore, plasma parameters can be adjusted to promote a controlled fluorination, avoiding the chemical etching of carbon atoms from the sample. The fluorination entails the conversion of the sp2 hybridization into sp3 and

Effect of the fluorination technique on the surface-fluorination patterning of double-walled carbon nanotubes

• Lyubov G. Bulusheva,
• Yuliya V. Fedoseeva,
• Emmanuel Flahaut,
• Jérémy Rio,
• Christopher P. Ewels,
• Victor O. Koroteev,
• Gregory Van Lier,
• Denis V. Vyalikh and
• Alexander V. Okotrub

Beilstein J. Nanotechnol. 2017, 8, 1688–1698, doi:10.3762/bjnano.8.169

• the fluorinated DWCNTs are attributed to distinct local surroundings of the attached fluorine atoms. Possible fluorine patterns realized through a certain fluorination technique are revealed from comparison of experimental NEXAFS F K-edge spectra with quantum-chemical calculations of various models

• . It is proposed that fluorination with F2 and BrF3 produces small fully fluorinated areas and short fluorinated chains, respectively, while the treatment with CF4 plasma results in various attached species, including single or paired fluorine atoms and –CF3 groups. The results demonstrate a

• possibility of different patterning of carbon surfaces through choosing the fluorination method. Keywords: double-walled carbon nanotubes; fluorination; NEXAFS; quantum-chemical modeling; Introduction Even after surface chemical functionalization, due to their inner shell double-walled carbon nanotubes

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

• Florian Rückerl,
• Daniel Waas,
• Bernd Büchner,
• Martin Knupfer,
• Dietrich R. T. Zahn,
• Francisc Haidu,
• Torsten Hahn and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 1601–1615, doi:10.3762/bjnano.8.160

• different polarization directions of the incident synchrotron radiation, as depicted in Figure 13. The data for a 3 nm thick F16CoPc film on top of MnPc are very similar to the corresponding absorption spectra of pure CoPc on gold [130]. This indicates that fluorination of CoPc has little impact on the

Calculations of helium separation via uniform pores of stanene-based membranes

• Guoping Gao,
• Yan Jiao,
• Yalong Jiao,
• Fengxian Ma,
• Liangzhi Kou and
• Aijun Du

Beilstein J. Nanotechnol. 2015, 6, 2470–2476, doi:10.3762/bjnano.6.256

• by taking both diffusion and selectivity into account. Our results are the first calculations of He separation in a defect-free honeycomb lattice, highlighting new interesting materials for helium separation for future experimental validation. Keywords: fluorination; gas purification; honeycomb

• systematically investigated by DFT calculations. At room temperature, the pristine 2D Sn is impermeable for noble gases. To increase the diffusion rate of noble gases, two practical strategies were proposed: stretch and fluorination. With a high concentration of uniform pores, 2D Sn-based materials exhibited

Plasma fluorination of vertically aligned carbon nanotubes: functionalization and thermal stability

• Claudia Struzzi,
• Mattia Scardamaglia,
• Axel Hemberg,
• Luca Petaccia,
• Jean-François Colomer,
• Rony Snyders and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 2263–2271, doi:10.3762/bjnano.6.232

• properties of the starting materials. Various techniques have been employed to achieve a controlled fluorination yield; however, the effect of contaminants is rarely discussed, although they are often present. In the present work, the fluorination of vertically aligned multiwalled carbon nanotubes was

• spectroscopy (FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) [10][18][19]. Although a large number of fluorination strategies and characterization routes have been reported, the choice of the precursor gas is a crucial issue that should not be underestimated due to the risk of

• of fluorine and noble gases mixtures, an important role for achieving optimal fluorination is played by the relative concentration of fluorine in the mixture during the plasma activation. The previous studies on vertically aligned carbon nanotubes (vCNTs) fluorinated by Ar/F2 plasma treatment allowed

Continuum models of focused electron beam induced processing

• Milos Toth,
• Charlene Lobo,
• Vinzenz Friedli,
• Aleksandra Szkudlarek and
• Ivo Utke

Beilstein J. Nanotechnol. 2015, 6, 1518–1540, doi:10.3762/bjnano.6.157

• of precursor molecules and hence induce transitions from the physisorbed to the chemisorbed state. This effect is neglected here, but can be incorporated into FEBIP models as in [17] for the case of fluorination caused by decomposition of XeF2. The initial concentration of physisorbed and

• dissociative chemisorption pathway, leading to fluorination of many surfaces [69][70][71][75]. The model in [17] is a variant of the above model of thermally activated chemisorption defined by Equation 40–Equation 52. Electron beam dwell time as a control parameter of the composition of materials deposited

Carbon nano-onions (multi-layer fullerenes): chemistry and applications

• Juergen Bartelmess and
• Silvia Giordani

Beilstein J. Nanotechnol. 2014, 5, 1980–1998, doi:10.3762/bjnano.5.207

• to a larger curvature increasing the degree of surface strain. Another example for the functionalization of CNOs in a highly reactive environment was published by Khabashesku et al., who directly fluorinated CNOs under a stream of F2 and H2 [28]. CNO fluorination was carried out in a custom-built

• reactor with different fluorination temperatures. The CNOs used in this study were prepared from carbon black by heating and the formed individual CNOs had diameters between 50 and 100 nm. HF was generated in situ under the given reaction conditions in a continuous flow of a F2 gas mixture (10% F2/90% He

• ) and H2. The successful fluorination led to an increase of the mass of the CNO material and the fluorinated CNOs (F-CNO) were well soluble in ethanol and other alcohols as well as in DMF. Characterization of the F-CNOs was carried out by a multitude of techniques such as FTIR, Raman and UV–vis

Carbon-based smart nanomaterials in biomedicine and neuroengineering

• Antonina M. Monaco and
• Michele Giugliano

Beilstein J. Nanotechnol. 2014, 5, 1849–1863, doi:10.3762/bjnano.5.196

• consists of coating CNTs with surfactants, peptides, polymers, or nucleic acids, which preserve their aromatic structure, and (ii) the covalent approach [37][38][39], by means of applying several protocols, such as oxidation in strong acids, fluorination [40], and Bingel [41] and Billups [42] reactions

CoPc and CoPcF₁₆ on gold: Site-specific charge-transfer processes

• Fotini Petraki,
• Heiko Peisert,
• Johannes Uihlein,
• Umut Aygül and
• Thomas Chassé

Beilstein J. Nanotechnol. 2014, 5, 524–531, doi:10.3762/bjnano.5.61

• possible molecule-to-metal back transfer, or a combination of these two [13][14]. The fluorination of phthalocyanines represents an ideal route for the tuning of the ionization potential (IP), a basic electronic parameter which can significantly affect the interface dipole and thus the energy level

• alignment [15][16]. In the context of applications, perfluorinated counterparts of Pcs have demonstrated a high performance and stability in air and are used as n-type channels in electronic devices [17][18]. It is interesting to see whether and how the fluorination of the molecules affects possible charge

Influence of particle size and fluorination ratio of CF_x precursor compounds on the electrochemical performance of C–FeF₂ nanocomposites for reversible lithium storage

• Ben Breitung,
• M. Anji Reddy,
• Venkata Sai Kiran Chakravadhanula,
• Michael Engel,
• Christian Kübel,
• Annie K. Powell,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 705–713, doi:10.3762/bjnano.4.80

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers) to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs. Keywords: aligned; carbon nanotubes; fluorination

• present polymer-based functionalization and the grafting of biomolecules (DNA molecules, glucose molecules, proteins, etc.) on VA-CNTs for biological applications. Finally, we present some less-common functionalization methods. 3.1 Functional groups Fluorination of VA-CNTs: During the past decade

• , fluorinated non-aligned carbon nanotubes have been intensively investigated because of their potential applications [76]. Fluorination has been reported to impact on the morphology and on the physical and chemical properties of the CNTs, which can be used, for instance, as new precursors for chemical