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Search for "microscopy" in Full Text gives 304 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions
Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33
- yield of 79%. Scanning electron microscopy (SEM) analysis revealed the deformation and reduction in size of SAOED particles upon milling. Interestingly, carbon determination experiments revealed that SAOED is quickly poisoned by organic matter, thus hampering recyclability. This can be to some extent
Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene
Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19
- by scanning electron microscopy. The intriguing optical properties of BPP and its derivatives may lead to their application as fluorophores. Keywords: benzo[rst]pentaphene; intramolecular charge transfer; nanocrystals; photoluminescence; polycyclic aromatic hydrocarbon; Introduction Polycyclic
- intriguing rod-like nano- to microcrystals and/or longer wires, which were visualized by scanning electron microscopy (SEM). Results and Discussion BPP 2 could be prepared by the “DPEX” reaction [12] in 60% yield on a 0.1 g scale from dialdehyde 1 with a concentration of 0.60 mM (Table 1, entry 1). However
Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory
Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16
- , various application examples of molecular photoswitches have been reported so far including volumetric 3D printing [12][13], photoresponsive semiconductors [14][15][16][17], photopharmacology [18][19], energy storage materials [20][21][22][23], data storage materials [24], super-resolution microscopy [25
Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases
Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270
- methodologies. The mesomorphous properties of these two sets of compounds were investigated by polarized optical microscopy (POM), differential scanning calorimetry (DSC), and small-and wide-angle X-ray scattering (S/WAXS) and compared to related fluorinated and non-fluorinated homologs. The results showed that
- –332 °C for Fn and above 340 °C for Gnm, probing their excellent thermal stability. All Fn and Gnm compounds display mesophases at room temperature. Their optical textures and phase-transition behaviors were observed via hot stage polarizing optical microscopy (POM). POM images were systematically
Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures
Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252
- microscopy (STM) [44], clarifying that 80% of the CDs formed the head-to-head and tail-to-tail repeating patterns in which the wheels were located next to each other on the same cavity side, whereas 20% of the CDs exhibited the head-to-tail structure. This direction was induced by the different strengths of
Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels
Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220
- supramolecular gels. Keywords: characterisation; electron microscopy; gelators; small angle scattering; supramolecular materials; Introduction Supramolecular gels are a versatile class of materials, and are of interest in many diverse applications from energy storage to cell culture [1][2]. The versatile
- characterisation of the larger structures present are microscopy and scattering techniques [12]. Across the literature, many investigations rely solely on one of these techniques alone to describe their system. However, both microscopy and scattering have limitations which may prevent a robust characterisation
- be feasibly analysed [15]. A recent review by Kubota et al. summarised both the spatiotemporal advantages and disadvantages, as well as the artefacts arising from sample preparation and imaging conditions in the microscopy of molecular self-assemblies [16]. When imaging supramolecular gels, atomic
Cage-like microstructures via sequential Ugi reactions in aqueous emulsions
Beilstein J. Org. Chem. 2024, 20, 2078–2083, doi:10.3762/bjoc.20.179
- pH value. According to atomic force microscopy (AFM) data, the resulting particles had a domain structure and were similar in appearance to raspberries [20]. An interesting feature of the resulting particles was the high efficiency as Pickering emulsifiers: even at a concentration below 0.3 g/L
- particles with a concentration of 0.3 g/L and a water/toluene ratio of 3:1. However, it was not possible to distinguish any details on the surface of the droplets using conventional and confocal microscopy (Figure 1). To do this, it was necessary to remove the solvent that interfered with obtaining a
- , which was monitored through the disappearance of isocyanide in the reaction medium using a color reaction [19]. Then the emulsion was applied to the glass surface and evaporated at a temperature of 50 °C. The resulting samples were analyzed using fluorescence microscopy at a wavelength of 490 nm. After
Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity
Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159
- force microscopy The study employed atomic force microscopy (AFM) in air to observe the bacterial morphological changes on the surface of S. epidermidis triggered by the impact of lanthipeptides. The concentrations of peptides were estimated based on the SDS gel band intensity, and we expect there is
- GraphPad (version 8.0.2). Atomic force microscopy AFM characterization was conducted using a MultiMode 8-HR (Bruker). Samples containing S. epidermis at an OD600 > 1 were incubated with the lanthipeptides at room temperature for 1 and 5 hours. Subsequently, 9 µL of the samples were combined with 1 µL of a
- significance was calculated with a t-test in GraphPad 8.0.2. Atomic force microscopy images (peak force mode) of S. epidermidis MIQ43 incubated with the different samples for 1 hour and 5 hours. From left to right: no treatment, CloA2 precursor peptide, cellulosin, CloA1 precursor peptide, clostrisin. All
Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds
Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142
- moiety. The excellent photoswitchability in organic medium and the photoresponsiveness in aqueous medium, driven by visible light, were investigated by UV–vis absorption spectroscopy. The assembled supramolecular nanostructures were confirmed by electron microscopy, while the supramolecular packing was
- Information File 1). Negative-stain transmission electron microscopy (TEM) was employed to investigate the supramolecular transformations in aqueous medium. An aqueous solution of DA11 (82 mM, 5.0 wt %) was diluted to 4.1 mM (0.25 wt %), revealing large-aspect-ratio supramolecular nanofiber assemblies bundled
- soft scaffold of DA11 was imaged by scanning electron microscopy (SEM) to reveal bundled nanofibers partially aligned with the long axis of the macroscopic soft scaffold (Figure 4b). The degree of alignment (structural parameters and orientational order) of macroscopic soft scaffolds of DA11 were
Monitoring carbohydrate 3D structure quality with the Privateer database
Beilstein J. Org. Chem. 2024, 20, 931–939, doi:10.3762/bjoc.20.83
- and, therefore, poorly resolved density regions, whereas in electron cryo-microscopy different conformations and compositions are averaged out during image classification and volume reconstruction [5]. Owing to these difficulties, it is not uncommon to find problematic carbohydrate structures in the
Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis
Beilstein J. Org. Chem. 2024, 20, 734–740, doi:10.3762/bjoc.20.67
- cooperate with the PKS “in trans” [11][12]. Notably, in B. subtilis the giant bacillaene biosynthesis machinery forms an organelle-like complex that can be observed through cryoelectron microscopy [13]. The structure elucidation of “bacillaene” through extensive NMR spectroscopic methods revealed the
Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments
Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30
- tip of a scanning tunneling microscope (STM) [11][34][35][36]. Owing to the subatomic resolution now available with scanning probe microscopy techniques (STM and non-contact atomic force microscopy, nc-AFM), the “precursor approach” has opened the way for in-depth structural and electronic
- ” is particularly interesting, since the as-prepared π-extended structures can undergo in-depth structural characterization and electronic investigations in situ at the single molecule scale, thanks to scanning probe microscopy and spectroscopy. The synthetic route relying on O-extrusion was thus
Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes
Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13
- through scanning tunneling microscopy [85]. For TCBDs bearing unsubstituted anilino (p-H2NC6H4–) groups, their conversion into the p-iodophenyl derivatives via the Sandmeyer reaction and subsequent post-functionalization via the Suzuki and Sonogashira coupling reactions are achieved [86]. In the reaction
Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations
Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10
- electron microscopy (TEM) is a technique that has been used for a long time to provide images of molecules, but also to monitor the reactions triggered by the energy transfer of the electron beam to the atoms that build the molecules. In particular, the advances in TEM as well as in methods to anchor
Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor
Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9
- microscopy (SEM) at different magnifications, as shown in Figure 1a–d. The images reveal a layered structure exhibiting a rough surface with agglomerated, irregular, and dense particles. Figure 2a–e shows the elemental mapping analysis of Pt-PCN conducted using SEM-EDX. A homogeneous distribution of Pt
Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio
Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7
- buoyancy resulting from particle porosity [22][23][27][28]. Indeed, the DWCNT agglomerates having corresponding size can be seen in the optical microscope image of the dispersion (Figure 1b). The shapes of DWCNTs in the dispersion were examined by scanning electron microscopy (SEM) and atomic force
- microscopy (AFM) (see Supporting Information File 1, Figure S2). In both images, rod-like DWCNTs were observed, while spaghetti-like agglomerates were hardly observed. The average length (L) and diameter (D) of the DWCNT samples were ≈2.9 μm and ≈2.1 nm, respectively. The L/D of the DWCNTs was 1378, which
- dispersion. The polarizing optical microscopy (POM) images exhibited alignment of the DWCNTs along the shear direction (Figure 4a,b). To estimate the order parameter, the polarized optical absorption measurement was conducted at different sample angles ranging from 0° to 90° at intervals of 10° (Figure 4c
Biphenylene-containing polycyclic conjugated compounds
Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141
- ]. In their study, they effectively synthesized POA 87 utilizing 2,3-dibromotetracene (85) as substrate at a temperature of 430 K, employing ultra high vacuum conditions on Ag(111). Subsequent scanning tunneling microscopy (STM) analyses unveiled not only the linear POA 87 resulting from surface
Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals
Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128
- positive and negative charge carrier transport of 1 and 2. The active layers of 1 or 2 were spin-coated from chloroform solutions (10 mg/mL). Scheme S1 in Supporting Information File 1 illustrates the device structure with the energy levels of the layers. Figure 5 shows atomic force microscopy (AFM) images
- order and polarized optical microscopy show small birefringent domains, indicating locally instead of macroscopic molecular alignment of the films (see Figure S2 in Supporting Information File 1). Figure 6 shows the log–log plots of the J–V experimental curves for 1 and 2 in both device structures. In
Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors
Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88
- microscopy [36][37]. In nature, chemical gradients and phase separation are maintained by compartmentalization in liposomes, micelles, and vesicles rather than at interfaces such as ITIES. Artificial photosynthesis systems are being designed to mimic this behavior and recently the field of artificial
pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene
Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45
- of a large number of nanoparticles. Conversely, solutions with concentrations below the CAC values did not show an apparent Tyndall effect (Figure S3 in Supporting Information File 1), which provides further support for the accuracy of the CAC values. Transmission electron microscopy (TEM) was used
Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme
Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40
- exhibited a micromolar and submicromolar binding affinity for ds-polynucleotides and inactivated a mutant of dipeptidyl peptidase enzyme E451A. Confocal microscopy revealed that the conjugate with the longer linker entered the HeLa cell membranes and blue fluorescence was visualized as the dye accumulated
- cellular uptake and intracellular distribution of Phen-Py-1 in HeLa cells by TCS SP8 X confocal microscopy. The results showed that the dye entered the HeLa cell membranes fast, and after 1 hour of incubation at 1 µM concentration, blue fluorescence was visualized as the dye accumulated in the cell
- binding (∆rH). The reaction Gibbs energies (∆rG) were calculated by using the following equation: ∆rG = −RTln(Ka). The entropic contribution to the binding Gibbs energy was calculated by the equation: T∆rS = ∆rH − ∆rG. Confocal microscopy: HeLa cells were cultured and maintained in complete high glucose
CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview
Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29
- . These prepared porphyrin nanowires were subjected to surface microscopy and fluorescence energy transfer experiments, which elucidated their stability and resistance to disassembly. Conclusion Cu(I)-catalyzed “click chemistry” is a well-established protocol for the facile access of complexes from simple
Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors
Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14
Preparation of β-cyclodextrin/polysaccharide foams using saponin
Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7
- correlated to the foam stability. Morphology of the matrices studied by scanning electron microscopy (SEM) The different microstructures of the samples have been analysed for the three polysaccharide combinations. Those of β-cyclodextrin/LBG matrices will be shown here, since all the polysaccharides
- different times and the percent emergence of the liquid fraction was plotted vs time (see also Figure 1). Characterization of matrices: Scanning electron microscopy (SEM) of gold-sputter-coated samples was carried out using a Phenom Pro 739 microscope. Infrared analysis was carried out for the crushed
Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements
Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184
- microscopy (HSM) analyses for all four complexes (Figures S9–S12 in Supporting Information File 1) and variable temperature powder X-ray diffraction (VTPXRD) analyses for β-CD·BES and β-CD·PRO (Figures S13 and S14 in Supporting Information File 1). The precise temperature onset values did not always
- performed on a Bruker Ultrashield 400 Plus Spectrometer (Billerica, Massachusetts, U.S.A.) and the program MestReNova was used to analyse the resulting data [48]. Thermal analysis Hot stage microscopy (HSM): The crystals were immersed in a small amount of silicone oil and heated at a constant rate of 10
- microscopy (HSM), variable temperature powder X-ray diffraction (VTPXRD) patterns, TGA, dTGA and DSC analytical data, details of electron counts derived from the Squeeze procedure, and geometrical parameters of the β-CD host molecules. Acknowledgements The authors acknowledge the University of Cape Town for
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