Search results

Search for "diffusion" in Full Text gives 307 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Controlling the reactivity of La@C82 by reduction: reaction of the La@C82 anion with alkyl halide with high regioselectivity

  • Yutaka Maeda,
  • Saeka Akita,
  • Mitsuaki Suzuki,
  • Michio Yamada,
  • Takeshi Akasaka,
  • Kaoru Kobayashi and
  • Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

Graphical Abstract
  • , assuming that La@C2v-C82 and the monoadducts have the same absorption coefficients. X-ray crystallography Black crystalline rods of 3a were obtained using the liquid–liquid bilayer diffusion method with 3a in a CS2 solution and an n-hexane solution in a glass tube (⌀ = 7 mm) at room temperature. The SC-XRD
PDF
Album
Supp Info
Full Research Paper
Published 11 Dec 2023

Active-metal template clipping synthesis of novel [2]rotaxanes

  • Cătălin C. Anghel,
  • Teodor A. Cucuiet,
  • Niculina D. Hădade and
  • Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

Graphical Abstract
  • validated by 1H-DOSY NMR experiments (Figure 3, and Supporting Information File 1, Figure S26) indicating that the macrocycle and the axle diffuse as a whole with a diffusion coefficient of 4.2 × 10−10 m2/s. Conclusion In summary, we introduced herein a new synthetic strategy of [2]rotaxanes that combined
PDF
Album
Supp Info
Full Research Paper
Published 20 Nov 2023

Selectivity control towards CO versus H2 for photo-driven CO2 reduction with a novel Co(II) catalyst

  • Lisa-Lou Gracia,
  • Philip Henkel,
  • Olaf Fuhr and
  • Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

Graphical Abstract
  • -dissolving the powder in acetonitrile and layering on top of diethyl ether (Et2O). Slow diffusion of the antisolvent Et2O allowed the growth of magenta-colored crystals. Interestingly, two different sets of data could be solved, which is an indication that compound 1 has two polymorphs, 1a and 1b (Figure 2
PDF
Album
Supp Info
Full Research Paper
Published 17 Nov 2023

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

  • Alessandro L. Alves,
  • Simone V. Bernardino,
  • Carlos H. Stadtlober,
  • Edivandro Girotto,
  • Giliandro Farias,
  • Rodney M. do Nascimento,
  • Sergio F. Curcio,
  • Thiago Cazati,
  • Marta E. R. Dotto,
  • Juliana Eccher,
  • Leonardo N. Furini,
  • Hugo Gallardo,
  • Harald Bock and
  • Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

Graphical Abstract
  • . The enhanced and blue-shifted emission at the transition to the isotropic phase arise from the excited isolated molecules, where the exciton decays radiatively without diffusion. For the isolated molecules, the more localized π-orbital results in a higher energy emission state. The same effect was
PDF
Album
Supp Info
Full Research Paper
Published 16 Nov 2023

Radical chemistry in polymer science: an overview and recent advances

  • Zixiao Wang,
  • Feichen Cui,
  • Yang Sui and
  • Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

Graphical Abstract
  • conventional radical polymerization. Most free radicals have an extremely short lifetime due to a diffusion-controlled termination process between two free radicals. The inevitable termination between radicals makes the synthesis of well-defined polymers and co-polymers very difficult. In addition, polymers
PDF
Album
Review
Published 18 Oct 2023

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

  • Jessica Villegas,
  • Bryce C. Ball,
  • Katelyn M. Shouse,
  • Caleb W. VanArragon,
  • Ashley N. Wasserman,
  • Hannah E. Bhakta,
  • Allen G. Oliver,
  • Danielle A. Orozco-Nunnelly and
  • Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

Graphical Abstract
  • , we first re-assessed the various extracts of the A. mexicana plant parts against this same panel, as our original study had only focused on the plant’s activities against six representative microbes [9]. Activities were assessed through a Kirby–Bauer disc-diffusion assay, measuring zones of
PDF
Album
Supp Info
Full Research Paper
Published 29 Sep 2023

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

  • Alexander C. Brannan,
  • Elvie F. P. Beaumont,
  • Nguyen Le Phuoc,
  • George F. S. Whitehead,
  • Mikko Linnolahti and
  • Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

Graphical Abstract
  • isomeric mixture of 4BGIPN. This is expectedly higher than the analogous Tg of 176 °C for the 4CzIPN material [13] due to a lower molecular mass of the latter (Figure S1, Supporting Information File 1). Single crystals for X-ray diffraction study were obtained by slow layer diffusion of hexanes into
  • ppm; Anal. calcd. for C60H32N14 (948.29): C, 75.94; H, 3.40; N, 20.66; found: C, 75.59; H, 3.54; N, 20.28; HRESIMS m/z: [M + Na]+ calcd. for C60H32N14Na, 971.2827; found, 971.2854. X-ray crystallography Crystals suitable for X-ray diffraction study were obtained by slow layer diffusion of hexanes
PDF
Album
Supp Info
Full Research Paper
Published 07 Sep 2023

Photoredox catalysis harvesting multiple photon or electrochemical energies

  • Mattia Lepori,
  • Simon Schmid and
  • Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Graphical Abstract
  • a two-photon process. DBU was found to quench the steady-state fluorescence of *PC1 with a quenching rate constant two orders of magnitude smaller than the diffusion rate constant in DMSO at 298 K and one order of magnitude greater under the borylation reaction conditions (i.e., 0.20 M DBU) than the
  • obtained by transient absorption spectroscopy with femtosecond pulsed laser excitation and were 2–3 orders of magnitude greater (e.g., keT (*PC1•−) = 6.8 × 1010 s−1) than the diffusion rate in DMSO (kdiff = 4.0 × 108 s−1 of 0.12 M 1d) confirming a preassociation of PC1•− and the substrate prior to PET
PDF
Album
Review
Published 28 Jul 2023

A new oxidatively stable ligand for the chiral functionalization of amino acids in Ni(II)–Schiff base complexes

  • Alena V. Dmitrieva,
  • Oleg A. Levitskiy,
  • Yuri K. Grishin and
  • Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2023, 19, 566–574, doi:10.3762/bjoc.19.41

Graphical Abstract
  • the C=N bond), diffusion controlled (the slope of the ln ipc vs ln v dependence is 0.48), and reversible; the direct and reverse peak separation value was 57 mV at 100 mV/s, and Ia/Ic peak current ratio was close to unity. This means that the radical anion of (GlyNi)L7 is stable, at least in the
PDF
Album
Supp Info
Full Research Paper
Published 27 Apr 2023

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

  • Jorge de Lima Neto and
  • Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

Graphical Abstract
  • antibacterial or antifungal activities were observed [55]. Ponnapalli and co-workers tested in an agar diffusion assay the isolated compounds corniculatolide A (4), 11-O-methylcorniculatolide A (5), 12-hydroxy-11-O-methylcorniculatolide A (6), isocorniculatolide A (7), and 11-O-methylisocorniculatolide A (8
PDF
Album
Review
Published 29 Mar 2023

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

  • Robert N. Goldberg,
  • Robert T. Giessmann,
  • Peter J. Halling,
  • Carsten Kettner and
  • Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

Graphical Abstract
  • . Concentration expressed as mol∙dm−3 has important advantages when dealing with transport properties (e.g., diffusion coefficient and transport number). In this document the word “concentration” is used with the understanding that “molality” or mole fraction could also have been used. The reaction equation and
PDF
Album
Perspective
Published 15 Mar 2023

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

  • Sedat Ünal,
  • Gamze Varan,
  • Juan M. Benito,
  • Yeşim Aktaş and
  • Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

Graphical Abstract
  • parameter of the release curve) value is a criterion used to illuminate the release from a polymeric matrix. “β” ≤ 0.75 indicates Fickian diffusion, while 0.75 < “β” < 1 indicates Fickian diffusion and controlled release combination [35]. The “β” value for the Weibull model was calculated as 0.396 and 0.434
  • for the 6-O-capro-β-CD and CS-(6-O-capro-β-CD) nanoparticle formulations, respectively. According to the Weibull model, CPT release kinetics from nanoparticles were found to be compatible with Fickian diffusion in SGF medium [36]. In the model-independent principal evaluation of in vitro release
  • profiles, this was considered as the rapid/burst and initial release of the drug adsorbed on the nanoparticle surface or encapsulated in the nanoparticle material matrix. It has been confirmed by mathematical modeling that the release is based on diffusion. This indicates the release of the CPT, which is
PDF
Album
Full Research Paper
Published 13 Feb 2023

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

  • Naoya Oku,
  • Saki Hayashi,
  • Yuji Yamaguchi,
  • Hiroyuki Takenaka and
  • Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

Graphical Abstract
  • yield compound 1 (0.7 mg). Nostochopcerol (1): [α]D22.4 −5.9 (c 0.01, MeOH); UV (MeOH) λmax, nm (log ε): 200 (1.7); HRMS–ESIMS (m/z): [M + Na]+ calcd for C19H34NaO4+, 349.2349; found, 349.2348; IR (ATR) νmax: 3350, 2921, 2852, 1601, 1457, 1195, 1103, 1015, 875, 696 cm−1. Paper disk-agar diffusion method
  • According to a procedure described in [6], the antimicrobial potency of chromatographic fractions was evaluated by a paper disk-agar diffusion method. Fractions at each purification stage were diluted to the same concentration with MeOH, and 10 μL aliquots were impregnated into 6 mm-diameter paper disks
PDF
Album
Supp Info
Letter
Published 09 Feb 2023

Catalytic aza-Nazarov cyclization reactions to access α-methylene-γ-lactam heterocycles

  • Bilge Banu Yagci,
  • Selin Ezgi Donmez,
  • Onur Şahin and
  • Yunus Emre Türkmen

Beilstein J. Org. Chem. 2023, 19, 66–77, doi:10.3762/bjoc.19.6

Graphical Abstract
  • ]. In the present work, the α-methylene-γ-lactam products 19 were in most cases isolated as oils after column chromatography. Fortunately, lactam product 19l turned out to be a solid, and high-quality crystals could be obtained via slow vapor diffusion of pentane into its CH2Cl2 solution. Single-crystal
PDF
Album
Supp Info
Full Research Paper
Published 17 Jan 2023

Modern flow chemistry – prospect and advantage

  • Philipp Heretsch

Beilstein J. Org. Chem. 2023, 19, 33–35, doi:10.3762/bjoc.19.3

Graphical Abstract
  • scalability, and higher sustainability are the most prevalent ones. To provide examples and explanation for these claims, “flash chemistry”, a term coined by late Yoshida [4] for reactions at the diffusion limit, i.e., reactions completed within milliseconds with proper mixing, showcases the fast heat- and
PDF
Editorial
Published 06 Jan 2023

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

  • Konstantin Lebedinskiy,
  • Volodymyr Lobaz and
  • Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

Graphical Abstract
  • diffusion coefficient by binding with a high-molecular-weight host serves as a reliable indicator for the determination of binding parameters in a case if, for example, no alternation of chemical shifts is observed on the NMR spectrum. The diffusion coefficient can be estimated by a DOSY experiment [37]. In
  • our case, a gradual, steady decline of tetracene's diffusion coefficient was detected by titration with 4, but it exceeded the measurement error only at the maximum concentration of the CD. Thus, this method discovers a poor supramolecular interaction where a reliable determination of the binding
PDF
Album
Supp Info
Full Research Paper
Published 25 Nov 2022

Synthesis, optical and electrochemical properties of (D–π)2-type and (D–π)2Ph-type fluorescent dyes

  • Kosuke Takemura,
  • Kazuki Ohira,
  • Taiki Higashino,
  • Keiichi Imato and
  • Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

Graphical Abstract
  • evaluated to be 0.28 V for OTK-2 and 0.35 V for OTT-2. Therefore, the E1/2ox for OTK-2 with the (D–π)2Ph-type structure is cathodically shifted by 0.07 V, compared with that for OTT-2 with the (D–π)2-type structure. Furthermore, we investigated the diffusion-controlled process form CV at different scan
  • negligible change during 20 cycles at a scan rate of 100 mV s−1, indicating diffusion control and good reversibility of the oxidation process (Figures S2b,c and S3b,c, Supporting Information File 1). The highest occupied molecular orbital (HOMO) energy level versus vacuum level was estimated from the E1/2ox
PDF
Album
Supp Info
Full Research Paper
Published 18 Aug 2022

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

  • Anas J. Rasras,
  • Mohamed El-Naggar,
  • Nesreen A. Safwat and
  • Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

Graphical Abstract
  • against the pathogenic fungal strains Aspergillus fumigatus and Candida albicans. The sensitivity of the organisms was assayed against the activity of tested compounds solutions (at 10 mg/mL concentration) using a modified agar well diffusion method with determination of the inhibition zone diameter in mm
  • inhibition zone diameter using the agar well diffusion method. The structure–activity relationship (SAR) elaborated that piperazines with aliphatic groups on the nitrogen atom are more active than those with aromatic substituents against the fungus C. albicans. On the other hand, compounds comprising
  • compounds 4a–v. In vitro antimicrobial activities of the synthesized compounds tested at 10 mg/mL by modified well diffusion agar method and expressed as mean inhibition zone diameter (mm). Minimum inhibitory concentrations (MIC, µg/mL) of the synthesized compounds determined by microdilution method
PDF
Album
Supp Info
Full Research Paper
Published 31 May 2022

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

  • Jannis A. Reich,
  • Miriam Aßmann,
  • Kristin Hölting,
  • Paul Bubenheim,
  • Jürgen Kuballa and
  • Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

Graphical Abstract
  • desired pressure (usually 1.7–2 mL/min). Another advantage is the reduction of film diffusion on the carriers. A key advantage of this setup is that sampling and reaction at high pressure can occur simultaneously and progress curves can be measured in one reactor. Prior publications investigating high
  • regression, the error given corresponds to the 95% confidence interval. All particles were pestled to remove potential diffusion limitations. All experiments were conducted at 40 °C and in potassium phosphate buffer. Since the pump is intended for UHPLC applications, a mixing chamber was installed for up to
PDF
Album
Full Research Paper
Published 20 May 2022

Synthesis of piperidine and pyrrolidine derivatives by electroreductive cyclization of imine with terminal dihaloalkanes in a flow microreactor

  • Yuki Naito,
  • Naoki Shida and
  • Mahito Atobe

Beilstein J. Org. Chem. 2022, 18, 350–359, doi:10.3762/bjoc.18.39

Graphical Abstract
  • time, extremely fast molecular diffusion, and expelling the reaction product to avoid over-oxidation or over-reduction. We have previously reported the electrochemical carboxylation of several imines in a flow microreactor to afford the corresponding α-amino acids in good to moderate yields [33][34][35
PDF
Album
Supp Info
Full Research Paper
Published 29 Mar 2022

DABCO-promoted photocatalytic C–H functionalization of aldehydes

  • Bruno Maia da Silva Santos,
  • Mariana dos Santos Dupim,
  • Cauê Paula de Souza,
  • Thiago Messias Cardozo and
  • Fernanda Gadini Finelli

Beilstein J. Org. Chem. 2021, 17, 2959–2967, doi:10.3762/bjoc.17.205

Graphical Abstract
  • reaction potential energy surface (PES). All procedures resulted in reaction paths with no evidence of any significant barrier, indicating that HAT steps with quinuclidine should proceed at faster rates than with DABCO, possibly at the diffusion limit. (We refer the reader to chapter 8 of Supporting
PDF
Album
Supp Info
Letter
Published 21 Dec 2021

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

  • Luke O. Jones,
  • Leah Williams,
  • Tasmin Boam,
  • Martin Kalmet,
  • Chidubem Oguike and
  • Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

Graphical Abstract
  • to its low toxicity and to control the release of compounds stored in the porous structure through one of four methods: diffusion-controlled, swelling-controlled, erosion-controlled, and stimulus-controlled [54]. A study by Koshy et al. reported a methacrylated gelatin (GelMA) cryogel implanted by
  • both cryogels and ceramics into a mould, and a physical cross-linker was used to realise the drug theophylline after stimuli had been achieved. Due to the layer system, drug release could occur without diffusion of the subsequent layers, controlling the speed of the release in the ceramic cryogel. In
PDF
Album
Review
Published 14 Oct 2021

(Phenylamino)pyrimidine-1,2,3-triazole derivatives as analogs of imatinib: searching for novel compounds against chronic myeloid leukemia

  • Luiz Claudio Ferreira Pimentel,
  • Lucas Villas Boas Hoelz,
  • Henayle Fernandes Canzian,
  • Frederico Silva Castelo Branco,
  • Andressa Paula de Oliveira,
  • Vinicius Rangel Campos,
  • Floriano Paes Silva Júnior,
  • Rafael Ferreira Dantas,
  • Jackson Antônio Lamounier Camargos Resende,
  • Anna Claudia Cunha,
  • Nubia Boechat and
  • Mônica Macedo Bastos

Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144

Graphical Abstract
  • in Figure 3 [32], may have better passive diffusion through the membrane of the target cell, increasing its concentration in the intracellular medium and consequently its activity. In relation to CC50 values of the compounds selected for the cell viability test (2c, 2d, and 2g), all were less potent
PDF
Album
Supp Info
Full Research Paper
Published 01 Sep 2021

Constrained thermoresponsive polymers – new insights into fundamentals and applications

  • Patricia Flemming,
  • Alexander S. Münch,
  • Andreas Fery and
  • Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

Graphical Abstract
  • low viscosity, high density of polymer segments and functional groups as well as a smaller hydrodynamic radius and larger diffusion coefficient compared to linear polymer chains in solution. Amphiphilic AB-type copolymers spontaneously form micelle structures above a critical concentration by self
PDF
Album
Review
Published 20 Aug 2021

Progress and challenges in the synthesis of sequence controlled polysaccharides

  • Giulio Fittolani,
  • Theodore Tyrikos-Ergas,
  • Denisa Vargová,
  • Manishkumar A. Chaube and
  • Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

Graphical Abstract
  • of the self-assembly of cellulose chains at the active site of the enzyme suggested that diffusion of the aggregated molecules and the monomers around the active center dictates the DP that can be obtained by enzymatic polymerization [70][71]. This could be the reason causing enzymatic reactions to
PDF
Album
Review
Published 05 Aug 2021
Other Beilstein-Institut Open Science Activities