Nanopatterns of arylene–alkynylene squares on graphite: self-sorting and intercalation

• Tristan J. Keller,
• Joshua Bahr,
• Kristin Gratzfeld,
• Nina Schönfelder,
• Marcin A. Majewski,
• Marcin Stępień,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2019, 15, 1848–1855, doi:10.3762/bjoc.15.180

• and e have the same orientation as the hexagons in the underlying graphene layer, and therefore the same orientation as proposed in the self-assembled monolayer of pure 2 (see Supporting Information File 1), and other large PAHs on HOPG [36]. However, 2 in Figure 3b and d is rotated by 30°. This is

• rather unexpected for such small molecular species. Moreover, while misorientations are commonly observed (e.g., in turbostratic graphite) [37], such a controlled rotation of (nano-)graphene(s) is rather difficult to achieve [38], but may exhibit unexpected electronic properties [39]. In addition, the

• behavior of molecules in nanoporous systems can be different as compared to the unhindered graphene lattice [40]. We can only speculate on the roles of the D3h symmetry of 2 vs. the D2h symmetry of the nanopore of 1a (and its relative orientation to the graphite lattice). An observation of 2 in a more

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

• equivalent. The systems discussed are polyaromatic molecules adsorbed to graphene and carbon nanotubes; dimers of alcohols and amines; cellulose crystals; and alcohols adsorbed onto cellulose surfaces. Keywords: adhesion energy; adhesive force; dispersion interaction; weak molecular interaction

• the attractive interaction between unlike subsystems, e.g., a graphene sheet and adsorbed molecules, whereas the attractive interaction between like subsystems, e.g., graphene sheets in graphite, is called cohesion. Nonetheless, the basic interactions are the same for adhesion and cohesion. We

• stabilization of parallel alkane chains, as well as the stabilization of aromatic molecules adsorbed to graphene or carbon nanotubes. Furthermore, we found that the stabilization energy of an adsorbent and several small adsorbate molecules increases when the latter are in close contact with each other. This

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• -xylose (139) into furfural (140) was performed in water-CPME (1:3, v/v) and heated in a commercial monowave microwave oven in the presence of 10 wt % of 138 for 50 min. A maximum furfural yield of 76% was obtained. A new sulfonated graphene catalyst GR-SO3H (145) was prepared in some steps. A mixture of

• vacuum. The resulting brown solid material was named as graphene oxide (GO, 142). In continuation, a solution of 5% sodium carbonate was added to the sonicated GO (142) in deionized water so that the pH was increased up to 9–10. 64% hydrazine hydrate was added as well. Then, the reaction mixture was

• heated to reflux for 24 h. After cooling down to room temperature, the solution was filtered, washed with 1 N HCl and acetone, and then dried. The resulted material was named as graphene (GR, 143). In order to sulfonate the GR (143), sodium nitrite and sulfanilic acid (144) were added to a sonicated

Functionalization of graphene: does the organic chemistry matter?

• Artur Kasprzak,
• Agnieszka Zuchowska and
• Magdalena Poplawska

Beilstein J. Org. Chem. 2018, 14, 2018–2026, doi:10.3762/bjoc.14.177

• commonly applied synthetic approaches for the modification of graphene-family materials. This work presents a critical assessment of the amidation and esterification methodologies reported in the recent literature, as well as a discussion of the reactions that apply diazonium salts. Common

• misunderstandings from the reported covalent functionalization methods are discussed, and a direct link between the reaction mechanisms and the basic principles of organic chemistry is taken into special consideration. Keywords: characterization; functionalization; graphene; modification; synthesis design

• ; Introduction In 2004, Geim and Novoselov reported the first experimental isolation of the graphene sheet and the measurement of its properties [1]. Since then, the researchers have presented many different applications of this special carbon nanostructure [2][3]. Graphene oxide (GO) and reduced graphene oxide

Steric “attraction”: not by dispersion alone

• Ganna Gryn’ova and
• Clémence Corminboeuf

Beilstein J. Org. Chem. 2018, 14, 1482–1490, doi:10.3762/bjoc.14.125

• electrostatics is not the largest stabilizing energetic contribution, it is nonetheless the one that defines the trend in the total interaction energy for a range of investigated dimers. Electrostatic stabilization in graphane and graphene dimers has been attributed to the charge transfer (σCH → σHC

• * hyperconjugative interaction) [17], and a similar argument was used to suggest the possibility of manipulating the band gap of patterned hydrogenated graphene C4H bilayer by an external electric field [27]. Furthermore, Schreiner et al. showed that approx. 10% of the total interaction energy in the tris(3,5-di

Are dispersion corrections accurate outside equilibrium? A case study on benzene

• Tim Gould,
• Erin R. Johnson and
• Sherif Abdulkader Tawfik

Beilstein J. Org. Chem. 2018, 14, 1181–1191, doi:10.3762/bjoc.14.99

• lead to higher order contributions, including 3rd-order effects between three multipoles, 4th-order etc., as detailed in, e.g., Dobson and Gould [2]. In certain cases, including graphene [28][29][30][31], this can lead to fundamental deviations from the simple model outlined above [18][31][32][33][34

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

Fluorogenic PNA probes

• Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

• probes [129]. Combination of PNA probes with nanomaterials as external quenchers/FRET partners Graphene oxide (GO) has been used extensively in combination with dye-labeled DNA for fluorescence-based DNA/RNA sensing [130][131]. Although ssDNA interacts strongly with GO via a combination of multiple

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• . First, a mechanochemical cracking yielded carboradical intermediates that were reacted with red phosphorus and then oxidized in the presence of air to produce graphene phosphonic acid 137 [116] (Figure 39). This material which is water soluble was used as a non-toxic flame-retardant. Conclusion

Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179

• layered materials such as graphite (to form graphene) [10], but it has also been employed in the formation of organometallic [11] and organic compounds [12]. Great success has been found in the treatment of waste water by ultrasonic irradiation, to remove heavy metals or degrade aromatic constituents [13

Ni nanoparticles on RGO as reusable heterogeneous catalyst: effect of Ni particle size and intermediate composite structures in C–S cross-coupling reaction

• Debasish Sengupta,
• Koushik Bhowmik,
• Goutam De and
• Basudeb Basu

Beilstein J. Org. Chem. 2017, 13, 1796–1806, doi:10.3762/bjoc.13.174

• , Jadavpur, Kolkata 700032, India. Fax: +91 33 24730957; Tel: +91 33 23223403 10.3762/bjoc.13.174 Abstract The present work demonstrates the C–S cross-coupling reaction between aryl halides and thiols using nickel nanoparticles (Ni NPs) supported on reduced graphene oxide (Ni/RGO) as a heterogeneous

• catalytic process has been established for the first time, and found to be best in the C–S cross-coupling reaction for Ni(0) and Ni(II) NPs of the average sizes 11–12 nm and 4 nm, respectively. Keywords: C–S cross-coupling; heterogeneous catalyst; Ni nanoparticle; reduced graphene oxide; thioether

• ) is thus far known to act as the only heterogeneous nanocatalyst for C–S cross-coupling with limited applications and poor yields [24]. In recent years, graphene-based composite materials have become popular because of their unique physical, mechanical and chemical properties [25][26][27]. Graphene, a

Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin

• Ana Franco,
• Sudipta De,
• Alina M. Balu,
• Araceli Garcia and
• Rafael Luque

Beilstein J. Org. Chem. 2017, 13, 1439–1445, doi:10.3762/bjoc.13.141

• this work, new transition metal-based catalysts were proposed to investigate their efficiency in vanillin production. Reduced graphene oxide supported Fe and Co catalysts showed high conversion of isoeugenol under mild reaction conditions using H2O2 as oxidizing agent. Fe catalysts were more selective

• employed [14][19][20][21]. However, the selectivity of vanillin still remains an important issue. In this work, we report the mechanochemical design of transition-metal-based catalysts supported on reduced graphene oxide support for the oxidation of isoeugenol into vanillin using H2O2 as oxidant. The

• catalytic support, RGO, a graphene derived material are normally produced by chemical reduction of graphene oxide (GO) [22][23]. The materials were prepared using a simple and effective ball milling approach and were characterized by different techniques. Results and Discussion The supported RGO materials

Mechanochemistry-assisted synthesis of hierarchical porous carbons applied as supercapacitors

• Desirée Leistenschneider,
• Nicolas Jäckel,
• Felix Hippauf,
• Volker Presser and
• Lars Borchardt

Beilstein J. Org. Chem. 2017, 13, 1332–1341, doi:10.3762/bjoc.13.130

• ]. For example, the preparation of nanocarbon structures such as graphene sheets or fullerenes [39][40][41] as well as porous carbonaceous polymers [42][43] have been conducted mechanochemically. Our work demonstrates that a templating approach can be transferred into the solvent-free environment of a

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• can be obtained. Typical substrates used are single/multi-walled carbon nanotubes, graphite, graphene or candle soot, amongst many others [15][17]. The crystalline make-up of top-down derived CDs is usually highly sp2 in character, which is transferred from the sp2-enriched starting materials, e.g

• ., graphite or graphene. Conversely bottom-up methodologies rely on the use of a molecular precursor which can be treated in such a way as to seed the formation of a CD. Typical starting materials include amino acids, citric acid, biomass and carbohydrates to name but a few, which can be reacted using thermal

Extrusion – back to the future: Using an established technique to reform automated chemical synthesis

• Deborah E. Crawford

Beilstein J. Org. Chem. 2017, 13, 65–75, doi:10.3762/bjoc.13.9

• industry, generally for the dispersion of materials (e.g., graphene or quantum dots) into polymers [7]. However, REX is also employed as a technique to synthesise polymers or to carry out post synthetic polymer modification (e.g., functionalisation of polymer chains) via organic transformations, which in

Stabilization of nanosized titanium dioxide by cyclodextrin polymers and its photocatalytic effect on the degradation of wastewater pollutants

• Tamás Zoltán Agócs,
• István Puskás,
• Erzsébet Varga,
• Mónika Molnár and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2016, 12, 2873–2882, doi:10.3762/bjoc.12.286

• decomposition [27][28]. Recently, various photocatalysts modified by CDs have been described. For instance, reduced graphene oxide/β-CD/titanium dioxide showed enhanced removal of phenol and Cr(VI) [29], graphene nanosheets with self-assembled nanolayer of TiO2 stabilized by β-CD resulted in improved

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• was observed at concentrations up to 333 μg/mL [73]. Separately, a facile and rapid MW-assisted method in water has been used to derivatize graphene nanosheets with (2-hydroxy)propyl-β-CD. The reaction involved the esterification of the HP-β-CD hydroxy groups by the carboxyl groups of graphene oxide

Electrochemical oxidation of cholesterol

• Jacek W. Morzycki and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

• immobilized on carbon nanotubes [59], metal nanoparticles [60] or graphene [61], and additionally decorated with metal nanoparticles [62] or modified with ionic liquids [63]. The application of composite electrodes, including silica sol–gel matrix with Prussian Blue [64], carbon nanotubes with zinc oxide

• inclusion complex with β-cyclodextrin functionalized graphene and emerged as a cholesterol sensing matrix. Methylene blue was then replaced by the cholesterol molecule and moved out in the buffer solution, where it was detected electrochemically by using the differential pulse voltammetric technique [71

Self-assembled monolayers of shape-persistent macrocycles on graphite: interior design and conformational polymorphism

• Joscha Vollmeyer,
• Friederike Eberhagen,
• Sigurd Höger and
• Stefan-S. Jester

Beilstein J. Org. Chem. 2014, 10, 2774–2782, doi:10.3762/bjoc.10.294

• models. Backbone geometries of the shape-persistent macrocycles with different interiors were derived by force-field modelling (Spartan ‘08) restricted to 2D (including interaction with a graphene layer with fixed atom positions), and extraannular octadecyloxy side chains in staggered (anti) conformation

Carbon nanomaterials

• Anke Krueger

Beilstein J. Org. Chem. 2014, 10, 1785–1786, doi:10.3762/bjoc.10.186

• carbon materials have entered the scene such as carbon nanotubes, carbon onions, nanoscale diamond and diamondoids. A major turning point was the appearance of graphene as a material available for in-depth investigations – spurred by the development of reliable production methods. The progress in terms

Pyrene-modified PNAs: Stacking interactions and selective excimer emission in PNA₂DNA triplexes

• Alex Manicardi,
• Lucia Guidi,
• Alice Ghidini and
• Roberto Corradini

Beilstein J. Org. Chem. 2014, 10, 1495–1503, doi:10.3762/bjoc.10.154

• ][15][16][17][18][19][20]. Furthermore, pyrene has been shown to favour self-assembly processes of supramolecular structures [21][22][23][24][25][26][27][28] and interact with carbon nanostructures such as nanotubes [29] or graphene [30], thus allowing to create composite material with special

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• the photocatalytic oxidative activation of NHPI by graphitic carbon nitride (g-C3N4) and visible light irradiation [65]. g-C3N4, the most stable allotrope of carbon nitride, is a two-dimensional polymer with a tri-s-triazine ring unit and a π-conjugated layered structure similar to graphene. It is a