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Search for "polymer" in Full Text gives 607 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands
Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26
- a chain coordination polymer, each unit consists of two NaH(hfac) molecules and one molecule of o-quinone 4 (Figure 2). The chain is constituted from sodium ions; each sodium ion is surrounded by five oxygens. Four of them belong to hfac molecules, the fifth one is a carbonyl oxygen atom of o
- from o-quinones 3, and 7–10 were generated directly before recording of EPR spectra according to the procedure described previously [56][57]. Active methylene compounds used for the preparation of gem-dithiolates. Fragment of coordination polymer chain of adduct 8 in the crystal phase. Hydrogen atoms
The preparation and properties of 1,1-difluorocyclopropane derivatives
Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25
- ]. The radical ring-opening polymerization (RROP) provides a synthetic route to fluoropolymers, which are useful materials [91]. The RROP of gem-difluorovinylcyclopropane (90) gave mainly the polymer with an unsymmetrical repeating unit, by the cleavage of the C2–C3 bond in the ring (Scheme 44, path a
Au(III) complexes with tetradentate-cyclam-based ligands
Beilstein J. Org. Chem. 2021, 17, 186–192, doi:10.3762/bjoc.17.18
- -tetraazacyclotetradecane), cyclen (1,4,7,10-tetraazacyclododecane)), ethylenediamine and triethylenetetraamine derivatives. Studies of Au(III)-cyclam modified complexes have been limited to arylated [16] or polymer-bound cyclams for selective uptake of Au(III) from water [17] as well as X-ray crystal structures [18][19
Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies
Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17
- Alexander Zika Franziska Grohn Department of Chemistry and Pharmacy & Interdisciplinary Center for Molecular Materials (ICMM) and Bavarian Polymer Institute (BPI), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, D-91058 Erlangen, Germany 10.3762/bjoc.17.17 Abstract Light- and
- binding constants Kx, which are related to the free energy change ΔG and thus due to ΔG = ΔH − TΔS, also the entropy change ΔS is revealed. Table 5 summarizes the results from the full titration curve fitting. The values correlate to the binding of one monomer of the polymer to Flavy and/or photoacid. For
- (partly) disassemble in the formation of the assemblies with the polymer such that poly(allylamine) competes with the Flavy–photoacid interaction. The rearrangement that takes place then also shows that the interaction of the poly(allylamine) with Flavy and the photoacid is preferred. The competition
Supramolecular polymers with reversed viscosity/temperature profile for application in motor oils
Beilstein J. Org. Chem. 2021, 17, 105–114, doi:10.3762/bjoc.17.11
- acid (GCP) or the aminopyridine carbonyl pyrrole carboxylic acid (ACP). At low temperatures, small cyclic structures are formed. However, at elevated temperatures, a ring–chain transformation leads to the formation of a supramolecular polymer. We demonstrate that this effect is dependent on the
- temperatures, e.g., caused by engine heat. Common VIIs are based on poly(methyl acrylate) (PMA) [1]. These systems are able to increase the viscosity at elevated temperatures by increasing their hydrodynamic radius [2]. This is based on the fact that PMAs occur as coiled polymer chains with lower hydrodynamic
- radii at lower temperature, while elevating the temperature leads to uncoiling of the polymer chain [3]. This results in a larger hydrodynamic radii and thus in an increase of viscosity [4]. The quantitative description of the viscosity improvement was developed by Dean and Davis in 1929 and coined the
Supramolecular polymerization of sulfated dendritic peptide amphiphiles into multivalent L-selectin binders
Beilstein J. Org. Chem. 2021, 17, 97–104, doi:10.3762/bjoc.17.10
- of rigid supramolecular polymers. Since multivalent sulfated supramolecular structures mimic naturally occurring L-selectin ligands, the corresponding affinity was evaluated using a competitive SPR binding assay and benchmarked to an ethylene glycol-decorated supramolecular polymer. Keywords: L
- to its functionalization with negatively charged sulfate groups. The binding behavior of dPGS to L-selectin has been thoroughly probed as dendrimer [26][27], conjugated to a polymer [28] or as amphiphilic adamantyl conjugates that are able to self-assemble on cyclodextrin vesicles [29]. Our group
- conditions, supramolecular polymer formation with a length of several hundred nanometers is observed at monomer concentrations as low as 25 µM. Evaluation of the L-selectin binding efficacy The L-selectin binding behavior of the sulfated supramolecular polymer resulting from II was assessed using a
Selected peptide-based fluorescent probes for biological applications
Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247
- polymerization reaction between polydiacetylene. PDA liposomes turn colorless to red upon formation of cross-linked liposomes. The fluorescence of the naphthimide is completely quenched due to the energy transfer from the fluorophore to the cross-linked polymer. However, addition of LPS restores the fluorescence
Dirhamnolipid ester – formation of reverse wormlike micelles in a binary (primerless) system
Beilstein J. Org. Chem. 2020, 16, 2820–2830, doi:10.3762/bjoc.16.232
- micelles behave similar to a polymer and can be nicely studied by rheology [12][13]. The underlying principle of wormlike micelles, which alter the rheology of the solvent is the same as for the “normal” system (micelles in water). However, the formation of wormlike micelles in organic solvents
Selective recognition of ATP by multivalent nano-assemblies of bisimidazolium amphiphiles through “turn-on” fluorescence response
Beilstein J. Org. Chem. 2020, 16, 2728–2738, doi:10.3762/bjoc.16.223
- the receptor with their complementary binding partners in the target analyte [15]. One of the ways to design multivalent systems is to connect the receptors through covalent linkages. Conjugated polymers and conjugated polymer electrolytes are prominent examples of covalently constructed multivalent
A consensus-based and readable extension of Linear Code for Reaction Rules (LiCoRR)
Beilstein J. Org. Chem. 2020, 16, 2645–2662, doi:10.3762/bjoc.16.215
- syntax for succinctly describing repeating MS units. The repetition structure is denoted by curly brackets, with a prefix of repetition times inside the brackets. For example, cellulose, which is a polymer of ᴅ-glucose residues joined by β-1,4 linkages, is represented as “{nGb4}” (RR1). If a ring
Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors
Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202
- scaling up can be achieved by numbering up. One of the most used photomicroreactors are capillaries wrapped around a light source. Such microcapillaries can be scaled up by connecting them either in parallel or in series (Figure 3a and Figure 3b). In a previous study, five polymer-based microcapillaries
Computational tools for drawing, building and displaying carbohydrates: a visual guide
Beilstein J. Org. Chem. 2020, 16, 2448–2468, doi:10.3762/bjoc.16.199
- . Subsequently, a glycosylation model can be prepared for carbohydrate polymer simulation using the prepreader.py script. Similarly, the doglycans.py script can be used to develop models for glycoproteins and glycolipids. Together, these tools are called doGlycans toolset. Although doGlycans is highly flexible
The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY
Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188
- properties of BODIPY and the biocompatibility of dextran. The BODIPY dextran nanoparticles were characterized regarding their size, morphology, polarity, and toxicity in vitro. We demonstrate the feasibility of mechanochemistry for boronic ester formation [23] to a glycan polymer as a route of conjugation
- (Figure 2B) according to the molar extinction coefficient (see Supporting Information File 1, Figure S1). Considering that dextran is a polydisperse polymer the functionalization was reported as weight ratio percent in the labeled polymer [26]. As shown in Figure 2B, a 1.6% w/w of 1 in the Dex-1b
- conjugate Dex-1b in aggregates or nanoparticles. Moreover, it is known that dye conjugation to a polymer even in small percentages can generate a large change in the environment of the chains affecting conformation and chain organization [36]. To assess the influence of hydrophobicity on the formation of
Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator
Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185
- with DNA/RNA. To study the interactions of 4 with DNA/RNA, we opted for long (>100 base pairs) polynucleotides, to ensure a large number of identical binding sites along one polymer (Table S2 in Supporting Information File 1). Thus, we used calf thymus (ct)-DNA as a typical B-helix structure with a
Synergy between supported ionic liquid-like phases and immobilized palladium N-heterocyclic carbene–phosphine complexes for the Negishi reaction under flow conditions
Beilstein J. Org. Chem. 2020, 16, 1924–1935, doi:10.3762/bjoc.16.159
- under continuous flow conditions. Results and Discussion Scheme 1 summarizes the synthetic approach used for the preparation of the functionalized polymers considered in this work. A commercially available PS-DVB bead-type macroporous chloromethylated polymer 1 (Merrifield resin with 20% DVB and 1.2
- corresponding Pd–NHC complexes 4a and 4b (Scheme 1) were obtained by treatment of the supported imidazolium species with Pd(OAc)2 in the presence of a base. The amount of immobilized NHC ligand was determined by elemental analysis, while the palladium loaded on the polymer was determined by ICP analyses (see
- -bromobenzoate (6) to form methyl 4-benzylbenzoate (7) was used to evaluate the activity of the palladium catalysts on polymer support (Scheme 2). The Negishi reaction is a potent cross-coupling reaction in organic chemistry. Notably, it has much value for the synthesis of fine chemicals and medicinal drugs [22
Design, synthesis and application of carbazole macrocycles in anion sensors
Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157
- different types of materials such as glass, crystal, or polymer. pH electrodes with glass membranes are the most used ISEs and produce highly selective responses over a wide range of concentrations. Polymeric membranes have gained popularity due to their robustness, the ability to fine-tune their properties
- and the ability to target a larger variety of ions compared to e.g. glass. Plasticizers may be required to improve transmembrane diffusion rates unless the polymer is self-plasticizing. Plasticized poly(vinyl chloride) (PVC), which was used in this study, is an example of a commonly used membrane
Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio
Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154
- -chain 3-hydroxy acids are the common building blocks with PHA, the microbial storage polymer. The structural similarities among 1–5 and PHA suggest a quite similar or even the same biosynthetic origin of these molecules, and hence a potential dehydrative modification at the hydroxy terminus of PHA. MS
Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2
Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152
- decaprenyl-P-P-GlcNAc-Rha, (glycolipid 2, GL2), which serves as a lipid carrier for arabinogalactan polymerization [7][8]. The latter enzyme, GlfT2, extends the product of GlfT1-catalyzed reaction, decaprenyl-P-P-GlcNAc-Rha-Galf2 (glycolipid 4, GL4), producing the lipid-linked galactan polymer [8]. Both
- synthesis of the lipid-linked galactan polymer. Complete experimental procedures, spectral characterization of all prepared compounds and copies of their 1H NMR and 13C NMR spectra are also provided. Supporting Information File 126: Experimental and analytical data. Funding The presented work was supported
One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?
Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143
- ; isosorbide; lignocellulosic biomass; Introduction Cellulose, a homopolymer of ᴅ-glucose, is the most abundant component of lignocellulosic biomass. Cellulose is a crystalline polymer due to its intra- and intermolecular hydrogen bond network. The conversion of cellulose to added value chemicals has received
- to sorbitol and 3) dehydration of sorbitol to isosorbide (Scheme 1). Isosorbide, a molecule obtained from biomass can find many applications such as additives, pharmaceuticals [2][3] and monomers for polymer industries [4][5][6]. For instance, one polymer obtained from isosorbide, poly(ethylene-co
Clickable azide-functionalized bromoarylaldehydes – synthesis and photophysical characterization
Beilstein J. Org. Chem. 2020, 16, 1683–1692, doi:10.3762/bjoc.16.139
- *) character of the T2 state. Although phosphorescent organic compounds are well investigated with respect to their photophysical properties in the crystalline state, in solution or physically embedded in polymer matrices, there is a significant lack of possibilities [61] for their targeted covalent attachment
Mechanochemical green synthesis of hyper-crosslinked cyclodextrin polymers
Beilstein J. Org. Chem. 2020, 16, 1554–1563, doi:10.3762/bjoc.16.127
- crosslinker. The polymer obtained exhibited the same characteristics as a CD-based carbonate NS synthesized in a solvent. Moreover, after the synthesis, the polymer was easily functionalized through the reaction of the nucleophilic carboxylic group with three different organic dyes (fluorescein, methyl red
- allow them to act as polyfunctional monomers, permitting the crosslinking with bi- or multifunctional chemicals, such as dianhydrides, diisocyanates, diepoxides, and dicarboxylic acids, etc. The polarity and size of the polymer network can be easily tuned by varying the type of the crosslinker and
- CD nanosponges, after crosslinking, comprise carbonate bonds between the cyclodextrin monomers. If this reaction is carried out under classical conditions in a N,N-dimethylformamide (DMF) solution, an amorphous crosslinked insoluble polymer is obtained. In general, carbonate nanosponges are insoluble
Heterogeneous photocatalysis in flow chemical reactors
Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125
- electrostatic repulsion that prevents the dye adsorption. 2.2 Organic semiconductor photocatalysis Polyaniline was the first conductive polymer reported by Henry Letheby in 1862 [99][100], but the potential of organic electronics was not realised until the 1960s, and the seminal work of Heeger, MacDiarmid, and
- polymer chains, charge transport is limited to intraplanar transport along the conjugated network. In crystalline and graphitic organic materials, the close packing of two-dimensional sheets permits interplanar charge transport in the third dimension, allowing the delocalisation of charge over several
- ]. Organic polymer materials, such poly(p-phenylene vinylene, εr(ω) = 2), typically have low εr(ω) values, which prevents the screening of excitons and leads to much stronger binding energies of 0.1–1 eV, which greatly exceeds the available thermal energy at room temperature [111][112][113]. This is
Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides
Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115
- with perfluorinated polymer film (PFA), and the bags are filled with the fluid to dispense. The pumping is accomplished by enclosing the bag in a metal clamshell, with contact surfaces made with an elastomer (Figure 3A). When compressed air is pumped in the clamshell, it squeezes the bag through the
- elastomer, and thus dispensing fluid. The elastomer sheets fully embrace the reagent bag, providing mechanical support. In this way, a soft polymer bag can be squeezed at a relatively high pressure: our prototype achieved pumping pressures up to about 1 MPa (10 bar). This type of pressure-driven pump, where
Activated carbon as catalyst support: precursors, preparation, modification and characterization
Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104
- with a production of 1011–1012 tons per year, followed by lignin as second most abundant raw material [16]. Lignin is a three-dimensional phenolic polymer and is responsible for the cementation of cellulose fibres in plants [17]. Hemicelluloses, predominantly xylan, are non-cellulosic polysaccharides
Synthesis and properties of quinazoline-based versatile exciplex-forming compounds
Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101
- Rasa Keruckiene Simona Vekteryte Ervinas Urbonas Matas Guzauskas Eigirdas Skuodis Dmytro Volyniuk Juozas V. Grazulevicius Department of Polymer Chemistry and Technology, Kaunas University of Technology, K. Baršausko g. 59, Kaunas 51423, Lithuania 10.3762/bjoc.16.101 Abstract Three compounds
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