Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• 10% for the carbon coated particles (Figure 4a). The resulting particles were also characterized by transmission electron microscopy (TEM), and corresponding images are shown in Figure 6a and 6b. The average particle diameter is ≈8 nm. Figure 6b shows nanoparticles sheathed and connected through

• lattices which might also help to provide longer paths for electrons to travel within the electrode. Summarizing, the Raman spectrum, the TGA measurements and the TEM images proves the success of the formation of a thin coating around the TiO2 particles. Currently, we are investigating the application of

• simultaneously introducing an anchor group. Afterwards, we showed the successful in situ synthesis of TiO2 particles with the block copolymer as a ligand on the surface. Raman spectroscopy and TEM images show that PILs are suitable carbon precursors and the herein introduced materials can be further applied as

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

• were characterized by using several techniques including BET, SEM, TEM, XRD, and IR spectroscopy. N2 adsorption/desorption isotherms of the reduced graphene sample (Figure 1a) can be classified as type IV corresponding to the mesoporous materials. The RGO sample showed a BET surface area of 103 m2 g−1

• mesoporous nature of the RGO can be easily observed from SEM images (Figure 2a and b), whereas metal-supported RGO materials show a smooth surface with decreased crystallinity. TEM images of RGO materials with different thickness show a sheet like morphology with different transparencies (Figure 3). Dark

• diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). N2 adsorption measurements were performed at 77 K by using a Micromeritics ASAP 2000 volumetric adsorption analyzer. The samples were degassed

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

• voltage of 20 kV. Transmission electron microscopy (TEM) was executed with a TEM Libra 200 system from Carl Zeiss Microscopy GmbH with an acceleration voltage of 200 kV. For the TEM, the sample powder was sonicated in acetone for 5 s. A lacey-carbon film on copper net (300 mesh) from Plano was used as TEM

• ) isopropoxide (Polymer-SF-3, orange). SEM (A) and TEM (B) images of the Carb-SF-3 sample. XRD-pattern of the polymeric precursor (Polymer-SF-3, orange), the carbonized composite (Comp-SF-3, black) and the carbon received by chlorine treatment (Carb-SF-3, red). Nitrogen physisorption isotherms for carbon samples

• acknowledge the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung, BMBF) for support of the Mechanocarb project (award number 03SF0498). DL wants to thank Kristian Schneider for the TEM measurement and the Leibniz-Institut für Polymerforschung Dresden e.V. for access to

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• impurities and dried, resulting in a dark brown solid. The formation process of a AgNPs/SugPOP-1 composite together with the related morphology of the matrix and AgNPs were studied by TEM. As shown in Figure 3a–d, with increased reaction time, the AgNPs gradually grow and the particle size become apparently

• measured at 77 K. For clarity, the isotherms of SugPOP-1 and SugPOP-2 were shifted vertically by 600 and 300 cm3 g−1, respectively. (b) PSD profiles of SugPOP-1–3 calculated by NLDFT analysis at 77 K. TEM images of the AgNPs/SugPOP-1 composite taken at different reaction times: (a) 0 h, (b) 8 h; (c) 16 h

Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids

• Simon Drescher,
• Vasil M. Garamus,
• Christopher J. Garvey,
• Annette Meister and
• Alfred Blume

Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99

• was studied as a function of temperature using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, and small angle neutron scattering (SANS). We show that our new bolalipid self-assembles into nanofibres, which transform into

• flexible nanofibres at 27 °C and further to small elongated micelles at 45 °C. Furthermore, the miscibility of the bolalipid with bilayer-forming phosphatidylcholines (DMPC, DPPC, and DSPC) was investigated by means of DSC, TEM, FTIR, and small angle X-ray scattering (SAXS). We could show that the PC

• side by side within the fibrous aggregate but slightly twisted relative to each other leading to a helical super structure of the fibres. This helicity was previously confirmed by cryo-transmission electron microscopy (cryo-TEM), high resolution atomic force microscopy (AFM) [26], and Monte Carlo

Expression, purification and structural analysis of functional GABA transporter 1 using the baculovirus expression system

• Jing Hu,
• Chris Weise,
• Christoph Böttcher,
• Hua Fan and
• Jian Yin

Beilstein J. Org. Chem. 2017, 13, 874–882, doi:10.3762/bjoc.13.88

• and size-exclusion fast protein liquid chromatography (SE-FPLC). A yield of 200–300 μg of the GAT1/GFP protein could be purified from 400–600 mL of infected Sf9 cells. The purified protein was analyzed by transmission electron microscopy (TEM), which revealed that the GAT1/GFP fusion protein was

• molecular weight of approximately 70 kDa, and the overlapping peak 2 (14.7 mL) corresponds to a molecular weight of 45 kDa, which was determined by comparison with the protein standards (Figure 4B). Transmission electron microscopy (TEM) analysis Cryogenic TEM (cryo-TEM) was employed to analyze both peaks

• hydrated state. After a BCA control, the fraction of peak 2 containing the larger amount of protein was characterized by cryo-TEM and showed a very monodisperse distribution of particles (Figure 5B) with a diameter in the 5–6 nm range, which might correspond to protein monomers. The peak 1 fraction

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

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

• ). In the absence of KH2PO4, irregular black carbon aggregates were obtained. Raman and TEM analysis showed both types of FCDs had graphitic crystallinity. This example highlights that an inorganic-based dehydrating agent could be used instead of a traditional diamine SPA to induce CD dehydration and

• . This is a widely employed strategy for improving the QY of CDs. The team was able to show that the presence of the dopant yielded N-doped CDs with a QY of 6%, which was superior to the N-free CDs. The resultant CDs afforded from the ultrasonic treatment were well dispersed, with TEM indicating graphite

• -dopant/surface passivation agent (Scheme 5) [33]. The resultant CDs had a QY of up to 12% (34-times higher than that of the undoped CDs). Interestingly, the N-doped CDs in this report had a 20 nm diameter, as determined by TEM, which is contrary to the generally held belief that CDs’ particular

Fast and efficient synthesis of microporous polymer nanomembranes via light-induced click reaction

• Qi An,
• Youssef Hassan,
• Xiaotong Yan,
• Peter Krolla-Sidenstein,
• Tawheed Mohammed,
• Mathias Lang,
• Stefan Bräse and
• Manuel Tsotsalas

Beilstein J. Org. Chem. 2017, 13, 558–563, doi:10.3762/bjoc.13.54

• with water [28]. Then the membrane was transferred to Cu-TEM grids. The obtained membrane size was 0.3 cm × 0.3 cm. Preparation of freestanding nanomembranes: To obtain freestanding nanomembranes, the CMP-films were grown on sacrificial substrates using the above-described procedure. The membrane was

Inhibition of peptide aggregation by means of enzymatic phosphorylation

• Kristin Folmert,
• Malgorzata Broncel,
• Hans v. Berlepsch,
• Christopher H. Ullrich,
• Mary-Ann Siegert and
• Beate Koksch

Beilstein J. Org. Chem. 2016, 12, 2462–2470, doi:10.3762/bjoc.12.240

• , in which no lag time was observed. To discover the morphology of the amyloid fibrils, a TEM (transmission electron micrograph) was obtained at 24 hours of incubation (Figure 3a). The TEM shows typical amyloid morphologies such as extended tubular fibers, some of them ending in funnels. The

• structures and a constantly low intensity for β-sheets over seven days of incubation (Figure 4a). Together with the TEM micrograph, which shows no sign of amyloid morphologies or other higher oligomers, the results suggest the inhibition of amyloid formation of KMF6 by enzymatic phosphorylation. Also, no

• to KFM6, with the intention to make it more prone to aggregation. However, only random structures were observed after seven days (Figure 3b). A TEM was taken 24 hours after dissolving and incubating the peptide. PCKFM6 shows no morphologies of amyloid fibrils, its preliminary states or other higher

Stimuli-responsive HBPS-g-PDMAEMA and its application as nanocarrier in loading hydrophobic molecules

• Yongsheng Chen,
• Li Wang,
• Haojie Yu,
• Zain-Ul-Abdin,
• Ruoli Sun,
• Guanghui Jing,
• Rongbai Tong and
• Zheng Deng

Beilstein J. Org. Chem. 2016, 12, 939–949, doi:10.3762/bjoc.12.92

• depends on the formation or breakdown of hydrogen bonds between polymer chains and water molecules as well as entropically driven effects. Figure 2C shows TEM images of HBPS-g-PDMAEMA aggregates. It was observed that the morphology of aggregates is inhomogeneous and the aggregates were composed of

• HBPS and HBPS-g-PDMAEMA; (B) 1H NMR spectra of HBPS and HBPS-g-PDMAEMA and (C) GPC curves of HBPS and HBPS-g-PDMAEMA. (A) The transmittance of HBPS-g-PDMAEMA aqueous solution of 10 mg/mL (pH 7); (B) pictures of aqueous solution of HBPS-g-PDMAEMA at 10 mg/mL below and above the LCST and (C) TEM images

Preparation of Pickering emulsions through interfacial adsorption by soft cyclodextrin nanogels

• Shintaro Kawano,
• Toshiyuki Kida,
• Mitsuru Akashi,
• Hirofumi Sato,
• Motohiro Shizuma and
• Daisuke Ono

Beilstein J. Org. Chem. 2015, 11, 2355–2364, doi:10.3762/bjoc.11.257

• (TEM) images demonstrate that the self-assembled CD nanogels consist of primary CD nanogel cores (Figure S3, Supporting Information File 1). To investigate the surface activity of CD nanogels, the surface tension of the aqueous solution was measured by the pendant drop method. The surface tensions of

• kV. Each Pickering emulsion sample was dried directly onto carbon tape and allowed to dry overnight before being sputter-coated with a thin layer of tungsten. Transmittance electron microscopy (TEM) studies were performed using a JEOL JEM-2100 operating at a voltage of 50 kV in order to clarify the

Self-assemblies of γ-CDs with pentablock copolymers PMA-PPO-PEO-PPO-PMA and endcapping via atom transfer radical polymerization of 2-methacryloyloxyethyl phosphorylcholine

• Jing Lin,
• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2015, 11, 2267–2277, doi:10.3762/bjoc.11.247

• copolymers able to form unique polymeric micelles in aqueous solution before the self-assembly with γ-CDs, as compared to PHEMA-PPO-PEO-PPO-PHEMA. The morphology of self-assembled aggregates of PMA-PPO-PEO-PPO-PMA in aqueous solution was observed by TEM. As shown in Figure S3, Supporting Information File 1

• and yields of PPRs. Compositions, GPC data and yields of PR-based multiblock copolymers. Supporting Information The Supporting Information File 1 contains 1H NMR spectra of BrPEPBr and PEP100M, GPC curves of BrPEPBr, PEP40M, PEP60M and PEP100M, TEM image of PMA-PPO-PEO-PPO-PMA in water and 1H NMR

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• be observed by high-resolution TEM. As a supramolecular “ion sponge”, the framework adsorbed various anionic guests, including drugs, peptides and DNA. These new 2D and 3D homogeneous SOFs all have defined cavities or pores, which are expected to display new, interesting properties [87]. Future

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• self-aggregated in chloroform–dioxane to form a gel. TEM images of the xerogel exhibited helical molecular tapes nanometer wide and micrometer long. A cyclic voltammetry (CV) study on 2b showed the redox properties expected for Pc and TTF, and doping of 2b in CH2Cl2 with I2 produced a radical cation

Synthesis and evaluation of the biostability and cell compatibility of novel conjugates of nucleobase, peptidic epitope, and saccharide

• Dan Yuan,
• Xuewen Du,
• Junfeng Shi,
• Ning Zhou,
• Abdulgader Ahmed Baoum,
• Khalid Omar Al Footy,
• Khadija Omar Badahdah and
• Bing Xu

Beilstein J. Org. Chem. 2015, 11, 1352–1359, doi:10.3762/bjoc.11.145

• ), which entangle to form stable networks (Figure 1B). This result is similar to the hydrogelation when mixing two nucleopeptides of the heterodimer [36]. In contrast, the mixture of 1 and 8 remains a solution. As shown in Figure 1A, the TEM of the solution of 1 + 8 reveals helical nanofibers with an

• average width of 10 ± 2 nm in the solution. This result indicates that the introduction of the glycan at the C-terminus of 5 increases the solubility of the nanofibers. The mixture of 7 and 8 also fails to result in a hydrogel. Moreover, the TEM of the solution of 7 + 8 hardly exhibits any ordered

• slightly increased in the treatment of the mixture of 1 + 8 (about 3% left) with proteinase K, comparing to the case of 8 incubated with proteinase K at 24 h. This result is consistent with TEM investigations showing that there are weak interactions between 1 and 8. Cell compatibility Cell compatibility is

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

• Daniel Schöne,
• Boris Schade,
• Christoph Böttcher and
• Beate Koksch

Beilstein J. Org. Chem. 2015, 11, 792–803, doi:10.3762/bjoc.11.89

• produces coiled-coil monomers. This effect was observed in all cases (Figure 2D). To resolve the morphology of the quaternary structures, TEM and/or Cryo TEM were applied to all peptides at pH 9 except for VW05; a representative image for R2A2 is shown in Figure 3. Negative staining TEM of 100 µM R2A2 at

• observed using Cryo TEM; however, they seem to be much shorter in length. However, resolving the microstructure of one fiber bundle using Cryo TEM was not possible. Surprisingly, fiber bundles could not be observed for peptides R2A4 and R2A5 whose sequences were extended by either two or three heptad

• exchange reaction with mercaptoundecanoic acid [38][39]. The obtained Au/MUA nanoparticles have an average diameter of 5.5 nm, as determined by TEM, and are monodisperse, as confirmed by DLS. An absorption maximum of 525 nm is observed for the Au/MUA nanoparticles in the absence of peptide, even over an

Synthesis of tripodal catecholates and their immobilization on zinc oxide nanoparticles

• Franziska Klitsche,
• Julian Ramcke,
• Julia Migenda,
• Andreas Hensel,
• Tobias Vossmeyer,
• Horst Weller,
• Silvia Gross and
• Wolfgang Maison

Beilstein J. Org. Chem. 2015, 11, 678–686, doi:10.3762/bjoc.11.77

• diffraction to confirm the formation of crystalline materials. The XRD pattern confirms the selective formation of pure ZnO wurtzite already at room temperature without the need of any further thermal treatment (Figure 3A). This data is in agreement with TEM micrographs, indicating the presence of spherical

• TEM images in Figure 6 show the coated particles after three rounds of washing with water and MeOH. Homogenous isolated spherical particles of about 25 nm diameter are observed for tripodal PEG-catecholate 3 (Figure 6C). This compares well to the expected size of 6 nm NPs coated with a 5 kDa PEG [50

• disc of anhydrous potassium bromide purchased from Merck. TEM analysis For TEM analysis, the functionalized particles were dispersed in MeOH and dropped onto 400-mesh carbon-coated TEM copper grids. The samples were analyzed using a JEOL JEM-1011 microscope, equipped with a LaB6 cathode and operated at

Potential of acylated peptides to target the influenza A virus

• Daniel Lauster,
• Damian Pawolski,
• Julian Storm,
• Kai Ludwig,
• Rudolf Volkmer,
• Henry Memczak,
• Andreas Herrmann and
• Sumati Bhatia

Beilstein J. Org. Chem. 2015, 11, 589–595, doi:10.3762/bjoc.11.65

• (TEM). First, the size of the supramolecular nanostructures formed by C18-PeBGF, C18-s2s, and C18-rs2s was analyzed by DLS at low concentration of 20 µM in PBS (10 mM, pH 7.4). For the analysis of C18-PeBGF, we observed a hydrodynamic diameter of 16.7 nm (PDI = 0.454) along with 10–15% bigger

• , under those conditions we observed supramolecular aggregates with a size larger than 1 µm indicating the strong potential of C18-PeBGF to organize as rather large assemblies. To visualize the organization of those assemblies, we employed TEM. To facilitate the structure identification, we used an even

• side-by-side assembly of these fibers, too. Importantly, cryo-TEM provides the same results (not shown) showing that formation of the large assemblies is not caused by contrast material. Preliminary TEM studies indicate similar assemblies for the other peptides used here. Our results indicate that the

Preparation and evaluation of cyclodextrin polypseudorotaxane with PEGylated liposome as a sustained release drug carrier

• Kayoko Hayashida,
• Taishi Higashi,
• Daichi Kono,
• Keiichi Motoyama,
• Koki Wada and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2014, 10, 2756–2764, doi:10.3762/bjoc.10.292

• obvious difference was not observed. These results suggest that the presence of DOX in PEG-LP scarcely alters the physicochemical properties of the PPRX. Additional studies by means of SEM or TEM may permit a more precise analysis and might confirm whether the LP structure is retained. Structure of CD

Anomalous diffusion of Ibuprofen in cyclodextrin nanosponge hydrogels: an HRMAS NMR study

• Monica Ferro,
• Franca Castiglione,
• Carlo Punta,
• Lucio Melone,
• Walter Panzeri,
• Barbara Rossi,
• Francesco Trotta and
• Andrea Mele

Beilstein J. Org. Chem. 2014, 10, 2715–2723, doi:10.3762/bjoc.10.286

• -linked polymers; cyclodextrin nanosponges; diffusion; HRMAS NMR spectroscopy; TEM; Introduction Cyclodextrin nanosponges (CDNS) are a novel, promising class of nanoporous, three-dimensional polymers with interesting properties of sorption of both organic and inorganic species [1][2][3]. Indeed, several

• behaviour can be related to the restricted diffusion of IP in the polymeric network due to the presence of nanopores originated during the cross-linking process. A visual description of the nanoporous structure of CDNSEDTA 1:4 is shown in Figure 4a. The TEM image was recorded on samples stained with Pb(NO3

• structure of the CDNSEDTA 1:8 is expected to show a high degree of heterogeneity in the distribution of pores, due to rearrangements caused by the steric hindrance. The TEM image of Figure 4b shows the details of the pores heterogeneity and the sponge-like morphology. The slightly superdiffusive behaviour

Linear-g-hyperbranched and cyclodextrin-based amphiphilic block copolymer as a multifunctional nanocarrier

• Yamei Zhao,
• Wei Tian,
• Guang Yang and
• Xiaodong Fan

Beilstein J. Org. Chem. 2014, 10, 2696–2703, doi:10.3762/bjoc.10.284

• –hydrophilic interactions between the inner core and the outer shell. The micelles were prepared by directly adding water to a DMF solution of P3 until the required amount of water for micelle formation was reached. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements were

• result, it can also be concluded that β-CD moieties were located on the outer shell of micelles. To visually examine the formation of the micelles, TEM images of MP1, MP2, and MP3 are shown in Figure 2. Spherical micelles were observed for MP1 (Figure 2A), whereas the morphologies of MP2 and MP3 were not

• . Experimental Experimental details can be found in the Supporting Information. Particle size distributions of MP1, MP2, and MP3 at 25 °C as determined by DLS. TEM images of P1 (A), P2 (B) and P3 (C) micelles. UV–vis spectra of LND solutions in the presence of MP1, MP2 and MP3 in buffer solutions. Particle size

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

• Véronique Nardello-Rataj and
• Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

• /polyacrylonitrile/copper nanorods composite fibers by adsorption and reduction. The composite fibers were fully characterized by FTIR, SEM, TEM, energy dispersive spectroscopy and X-ray photoelectron spectroscopy. The results indicated that the copper nanorods were not only successfully synthesized on the surface

Synthesis of novel conjugates of a saccharide, amino acids, nucleobase and the evaluation of their cell compatibility

• Dan Yuan,
• Xuewen Du,
• Junfeng Shi,
• Ning Zhou,
• Abdulgader Ahmed Baoum and
• Bing Xu

Beilstein J. Org. Chem. 2014, 10, 2406–2413, doi:10.3762/bjoc.10.250

• makes conjugate 3 or 4, however, is unable to result in hydrogelation (Supporting Information File 1, Figure S2A and S2B). The corresponding TEM images showed that conjugates 1–4 all form aggregates (upon drying) without ordered structures. Meanwhile, the removal of the saccharide from the SAN-type

• : General section, experimental section, TEM images of solutions of 1–8. Acknowledgments This work was partially supported by grant from NIH (R01CA142746) and a grant from KAU (44-130-35-HiCi). We thank the Brandeis EM facility at Brandeis University. D.Y. is grateful for a scholarship from the Chinese

Supercritical carbon dioxide: a solvent like no other

• Jocelyn Peach and
• Julian Eastoe

Beilstein J. Org. Chem. 2014, 10, 1878–1895, doi:10.3762/bjoc.10.196

• and HAuCl4 were solubilised within the IL domains, which were shown to be spherical micelles by transmission electron microscopy (TEM). The group also observed an increase in Ptrans with increased w value, as expected (w = 0.1–0.8) [54]. Chandran et al. have mapped the formation of reverse IL micelles