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Search for "morphology" in Full Text gives 194 result(s) in Beilstein Journal of Organic Chemistry.
An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone
Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40
- water-in-oil (w/o) microemulsion (water/Brij@30/n-heptane). This methodology has been previously used in our laboratory [27][28]. We first explored the morphology, size and dispersion of Pd nanoparticles supported on Vulcan XC72R carbonaceous material (Pd/C electrocatalysts) using TEM micrographs. As
- is the Toray paper support. Morphology, size and dispersion of Pd nanoparticles in Pd/C were analysed by a transmission electron microscopy (TEM) using a JEOL JEM-2012 instrument with an accelerating voltage of 300 kV. The TEM was connected with an energy dispersion X-ray (EDX) for the analysis of
The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands
Beilstein J. Org. Chem. 2017, 13, 2842–2853, doi:10.3762/bjoc.13.276
- nucleation process, an elongation phase and a final plateau linked to the morphology and the amount of fibrils formed at the end of the aggregation process. Compounds 1a–4a and 1b–4b were tested at compound/Aβ1-42 ratios of 10:1 and 1:1. None of the Boc-N-protected pentapeptides 1a–4a displayed inhibitory
Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin
Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248
- aggregates with the size of hundreds of nm in the 100 mM sample (Figure 4C). It is evident that the method of aggregation and the morphology of the specimen vary with increasing concentration. Sonication, conducted for 2 mM and 100 mM samples, resulted in a diametrically different arrangement of the fibers
- ) filtration. Distribution functions for 2-O- (2a), 3-O- (2b), and 6-O- (2c) NA-γ-CD regioisomers in 50% MeOH (v/v). Volume-weighted distribution functions for the 3-O- (2b) and 6-O- (2c) NA-γ-CD regioisomer at different temperatures. Effect of increasing concentration and sonication on the morphology of the 3
- concentration and sonication on the morphology of the 2-O-derivative 2a. A: 2 mM unsonicated specimen; B: 20 mM unsonicated specimen; C: 100 mM sonicated specimen. The arrow indicates an aggregated particle. Scale bars: 50 nm, inset: 10 nm. Effect of increasing concentration and sonication on the morphology of
New bio-nanocomposites based on iron oxides and polysaccharides applied to oxidation and alkylation reactions
Beilstein J. Org. Chem. 2017, 13, 1982–1993, doi:10.3762/bjoc.13.194
- three materials (Table 1). The materials exhibited, in general, satisfying surface areas and pore volumes, particularly taking into account their preparation methodology. Electron microscopy The morphology of the nanomaterials was determined by scanning electron microscopy (SEM) and transmission
Solvent-free sonochemistry: Sonochemical organic synthesis in the absence of a liquid medium
Beilstein J. Org. Chem. 2017, 13, 1850–1856, doi:10.3762/bjoc.13.179
- orange) but there was a clear separation between the two solids, indicating that the variation of particle size and morphology was too great for the reaction to proceed quantitatively. Therefore, both reagents were ground and sieved to both be fine powders of particle size <500 µm. A ca. 0.2 g mixture
An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation
Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166
- relatively easy to prepare and can be obtained in different size and morphology by essentially controlling the synthetic method and experimental conditions. As a result of the excellent catalytic activity of NPs, they can be used under mild and, in some cases, in environmental sustainable conditions. In
- from the same H2PdCl4 and PVP aqueous solution using MW irradiation (see Supporting Information File 1). The morphology and size of the Pd NPs was determined by TEM micrographs. Unfortunately, these MW-synthesized NPs proved to be inactive as catalysts in the Mizoroki–Heck coupling reaction between 1a
- (20 ± 10) nm with high dispersion in size (Figures S1 and S2, Supporting Information File 1). However, these bigger NPs were still active as catalysts, since with this larger NPs several catalytic cycles were performed (Figure 1). The morphology of the NPs like a “blackberry” appeared not to be
Block copolymers from ionic liquids for the preparation of thin carbonaceous shells
Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163
- in PIL block copolymers due to their demixed morphology or (ii) the control of ion conduction near surfaces, if PIL brushes are fixed to a surface [13]. This last example of a spatially restricted access of ions to a surface can be very interesting in combination with redox reactions [14][15], a case
The chemistry and biology of mycolactones
Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159
New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties
Beilstein J. Org. Chem. 2017, 13, 1583–1595, doi:10.3762/bjoc.13.158
- properties of the prepared compounds were investigated by UV–vis absorption spectroscopy and cyclic voltammetry. Electrochemical oxidation of these heterocycles resulted in the formation of thin films on the surface of an ITO working electrode. The morphology of grown films has been investigated by means of
- executed the electrochemical oxidation of compounds 6–8b using ITO covered glass plate as a working electrode. These processes resulted in the formation of thin films on the surface of the working electrode. Cyclic voltammograms, film images and the study of the morphology of their surface are presented in
Mechanochemical synthesis of graphene oxide-supported transition metal catalysts for the oxidation of isoeugenol to vanillin
Beilstein J. Org. Chem. 2017, 13, 1439–1445, doi:10.3762/bjoc.13.141
- 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
Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction
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
Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience
Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114
- fractions extracted from never-dried delignified spruce wood. In this case, the observed morphology was of the type “nanostrips” that had a characteristic thickness and width of about 0.5 nm and 4 nm, respectively. The thickness is an indication that the nanostrips are made up of only one monolayer of
Glyco-gold nanoparticles: synthesis and applications
Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100
- (i.e, AgNO3 or cetyltrimethylammonium bromide, CTAB), a control over the core morphology can be implemented with this methodology, as reported for the synthesis of mannose and galactose functionalized nanorods and nanostars [24] or glucosamine-coated nanostar AuNPs [22]. Respect to other methodologies
- devices [31][32]. Furthermore, in vitro and in vivo short term reduced toxicity of AuNPs has been widely documented [10][33][34][35][36][37][38]. AuNPs own a number of peculiar optical properties, strongly dependent on the size and the morphology of the metallic core. When AuNP dimension is comparable to
- . This phenomenon consists in a collective oscillation of the free electrons of the metal, induced by the light impinging on the AuNPs [31][39]. The AuNP surface plasmon resonance is dependent upon a vast number of parameters like size, shape, morphology and environment surrounding AuNPs [40]. By
Aggregation behaviour of a single-chain, phenylene-modified bolalipid and its miscibility with classical phospholipids
Beilstein J. Org. Chem. 2017, 13, 995–1007, doi:10.3762/bjoc.13.99
- of aggregates, samples for TEM were prepared below the first transition as well as between the first and the second transition of PC-C18pPhC18-PC. At about 7 °C, the TEM image depicts a dense network of long nanofibres (A). The morphology of these fibres changes with increasing temperature. At 36 °C
Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications
Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87
- will simultaneously decrease their processability in solution. This will result in the reduced formation of the desired bicontinuous morphology with the acceptor [16]. Hence, when designing new molecules for OPV applications, a subtle balance between lowering the band gap, crystallinity, and solubility
- -withdrawing or electron-donating groups [23][24]. Substitutions can be used to tune the band gap, energy levels, solubility, packing of material and morphology [8]. Among them, the introduction of fluorine has attained great interest because of its small size and strong electron-withdrawing nature, and
- planarity of the molecules. To understand the photovoltaic results, we have also investigated the morphology of the active layers of the devices by tapping mode AFM. With this method, information about the topography as well as phase images as shown in Figure S2 (Supporting Information File 1) can be
Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes
Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73
- support material, e.g., acid/base properties [184][185], morphology, grain size [186], porosity [187], strong metal–support interactions, swelling propensity [188]). In propyne hydrogenation, for instance, catalyst resistance was shown to decrease with increasing acidity of the support [189]. In order to
Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications
Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67
- distribution (1–2 nm) but little morphological uniformity. On the other hand, Chi-CDs appear to have a distinctly spherical morphology with a size range of 2–10 nm and Alg-CDs also exhibit a distinct spherical morphology with a size range of 2–4 nm. Interestingly, an inverse correlation between the size of the
- cyclodextrin utilised, with each CD showing a green emission under UV irradiation and excitation-independent emission from 360 to 460 nm excitation, which is typical of a uniform morphology. The authors proposed that the uniform emission could be attributed to either the uniform size distribution or the
Supramolecular frameworks based on [60]fullerene hexakisadducts
Beilstein J. Org. Chem. 2017, 13, 1–9, doi:10.3762/bjoc.13.1
- and PXRD measurements in combination with BFDH morphology calculations indicated the structural integrity of the material and the fact that the pore channels are located along the long fiber axis (see Figure S15 in Supporting Information File 1). Thermal treatment of crystalline samples under a
Effects of solvent additive on “s-shaped” curves in solution-processed small molecule solar cells
Beilstein J. Org. Chem. 2016, 12, 2543–2555, doi:10.3762/bjoc.12.249
- separation. This yields much better performing devices, with improved curve shape, demonstrating the importance of morphology control in BHJ devices and improving the understanding of the role of solvent additives. Keywords: current voltage analysis; morphology; organic solar cells; Introduction Tremendous
- architecture choices can lead to non-ideal electronics at electrode interfaces and severely limit the performance of a materials system. In particular, the fill factor (FF), which is simply a metric describing the field dependence of current, can be particularly sensitive to changes in morphology or
- shown by Tan and co-workers that in some cases, when PEDOT limits the voltage in solar cells, casting methanol on top of the layer will improve efficiency [63]. The methanol has been shown to effectively deepen the work function of the anode layer while not significantly disrupting the morphology
Inhibition of peptide aggregation by means of enzymatic phosphorylation
Beilstein J. Org. Chem. 2016, 12, 2462–2470, doi:10.3762/bjoc.12.240
- multiple conditions [1]. The morphology ranges from liquid crystals to ribbons, rigid nanotubes and funnels [2]. Although amyloid aggregates are mostly known for pathologic events like Alzheimer’s and Parkinson’s disease or type two diabetes [3][4][5][6], they also combine the potential for applications
- , 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
- position of the phosphate group can influence the amyloid formation and even the morphology of the formed fibrils [54][64]. Determining the relative contributions of the above factors to the role of phosphorylation in the amyloid forming pathway is a major challenge, however, crucial for the molecular
High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension
Beilstein J. Org. Chem. 2016, 12, 2298–2314, doi:10.3762/bjoc.12.223
- −2, Voc = 0.90 V, FF 74.1% and PCE of 9.3% [14], showing the batch to batch reproducibility in device data for molecular materials. Except for BMR, the FFs for SVA devices lie above 70%, indicating excellent morphology development. The best device contains BQR with a PCE of 9.4% and a Jsc = 15.3 mA
- those for BTR, except for a significant drop in Voc to 0.88 V from 0.92 V. One can only speculate on the cause of the Voc drop until further structural characterisation of the thin films is completed. The poor Jsc and FF for the BT8R devices indicates a poor development of morphology and indicates that
- BHJ devices leads to an improvement in overall device performance [22]. The underlying reason for the improved performance in these ternary devices is not yet clear with a combination of favourable morphology, energy level cascading and recombination in the ternary blend being suggested [23][24
Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties
Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205
- thin-film microstructure playing such a key role in the optoelectronic and charge transport properties of conjugated polymers, block copolymers naturally appear as useful tools for tailoring the thin-film morphology [1][2][3][4][5]. The propensity of some block copolymers to phase segregate at the nano
- , the morphology of the resulting ternary blend film can be more stable over long periods of time, even under thermal annealing [14][20][21]. However, the synthesis of block copolymers can be difficult to control, particularly in the case of step-growth polymerizations that are often used to synthesize
- key role in the morphology control and the self-assembly behavior of these polymers [7][22][23]. The Grignard Metathesis (GRIM) polymerization, also known as the Kumada catalyst transfer polymerisation (KCTP), is a popular method to synthesize conjugated block copolymers because its chain growth
Hydroxy-functionalized hyper-cross-linked ultra-microporous organic polymers for selective CO2 capture at room temperature
Beilstein J. Org. Chem. 2016, 12, 1981–1986, doi:10.3762/bjoc.12.185
- S4). To investigate the morphology of both compounds we performed a field emission scanning electron microscope (FESEM) study. The morphology of HCP-91 can be described as agglomerated particles consisting of small particles without any distinct shape (Figure 2c and Figure S5). But in case of HCP-94
- , a clear capsule-type of morphology was found in the FESEM (Figure 2d and Figure S6). After all characterizations and proper desolvation of both compounds, we investigated their porosity. First, we measured the N2 adsorption at 77 K. The N2 uptake for HCP-91 was found to be 595 mL/g, whereas that for
Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics
Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182
- higher FF, and a lower Jsc. The lower Jsc may be due to several factors, including purity, film thickness, morphology and charge recombination differences. Further studies are underway to better understand these results and will be reported separately. Conclusion In conclusion, four fluorinated WS3
Effect of the π-conjugation length on the properties and photovoltaic performance of A–π–D–π–A type oligothiophenes with a 4,8-bis(thienyl)benzo[1,2-b:4,5-b′]dithiophene core
Beilstein J. Org. Chem. 2016, 12, 1788–1797, doi:10.3762/bjoc.12.169
- best performance for cells based on COOP-capped BDT derivatives [21][22][23][35][36][37]. Surface morphology of the blended films The surface morphology of the COOP-nHT-TBDT:PC61BM films was scrutinized with atomic force microscopy (AFM). Figure 4 depicts the topological images of the blended films
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