Tag: M.W=200-250

Oschmann, Bernd; Bresser, Dominic; Tahir, Muhammad Nawaz; Fischer, Karl; Tremel, Wolfgang; Passerini, Stefano; Zentel, Rudolf published the artcile< Polyacrylonitrile Block Copolymers for the Preparation of a Thin Carbon Coating Around TiO2 Nanorods for Advanced Lithium-Ion Batteries>, Safety of Perfluorophenyl acrylate, the main research area is polyacrylonitrile block copolymer carbon coating titania nanorod lithium battery; RAFT-polymerization; TiO2 nanorods; carbon coating; lithium-ion batteries; poly­acrylonitrile.

Herein, a new method for the realization of a thin and homogeneous carbonaceous particle coating, made by carbonizing RAFT polymerization derived block copolymers anchored on anatase TiO2 nanorods, is presented. These block copolymers consist of a short anchor block (based on dopamine) and a long, easily graphitizable block of polyacrylonitrile. The grafting of such block copolymers to TiO2 nanorods creates a polymer shell, which can be visualized by at. force microscopy (AFM). Thermal treatment at 700° converts the polyacrylonitrile block to partially graphitic structures (as determined by Raman spectroscopy), establishing a thin carbon coating (as determined by transmission electron microscopy, TEM, anal.). The carbon-coated TiO2 nanorods show improved electrochem. performance in terms of achievable specific capacity and, particularly, long-term cycling stability by reducing the average capacity fading per cycle from 0.252 mAh g-1 to only 0.075 mAh g-1.

Macromolecular Rapid Communications published new progress about Annealing (of polyacrylonitrile block). 71195-85-2 belongs to class esters-buliding-blocks, and the molecular formula is C9H3F5O2, Safety of Perfluorophenyl acrylate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Arnold, Rachelle M.; Sheppard, Gareth R.; Locklin, Jason published the artcile< Comparative Aminolysis Kinetics of Different Active Ester Polymer Brush Platforms in Postpolymerization Modification with Primary and Aromatic Amines>, COA of Formula: C9H3F5O2, the main research area is aminolysis kinetics active ester polymer brush postpolymn modification.

The kinetics of aminolysis between two different active ester polymer brush platforms, poly(4-pentafluorophenyl acrylate) (poly(PFPA)) and poly(N-hydroxysuccinimide-4-vinyl benzoate) (poly(NHS4VB)), are compared using primary and aromatic amines with varying reactivity toward postpolymn. modification. UV-vis was used to monitor the aminolysis of both brush platforms with 1-aminomethylpyrene (AMP), 1-aminopyrene (AP), and Ru(bpy)2(phen-5-NH2)(PF6) (Ru2+A). Using a pseudo-first-order kinetics model, the pseudo-first-order rate constant (k’) was calculated for each system. The k’ of poly(PFPA) modified with AMP, AP, and Ru2+A were 2.46 × 10-1, 5.11 × 10-3, and 2.59 × 10-3 s-1, resp., while poly(NHS4VB) can only be functionalized with the alkyl amine, albeit at a slower rate constant, k’ of 3.49 × 10-3 s-1, compared to that of poly(PFPA) with AMP. The kinetics of surface-initiated photopolymerization of PFPA from oxide surfaces was also studied as an effective method to control grafting d. and film thickness.

Macromolecules (Washington, DC, United States) published new progress about Aminolysis kinetics. 71195-85-2 belongs to class esters-buliding-blocks, and the molecular formula is C9H3F5O2, COA of Formula: C9H3F5O2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Gu, Yuanyun; Zhang, Zhen; Wang, Yan-En; Dai, Ziteng; Yuan, Yaqi; Xiong, Dan; Li, Jie; Walsh, Patrick J.; Mao, Jianyou published the artcile< Benzylic Aroylation of Toluenes Mediated by a LiN(SiMe3)2/Cs+ System>, Related Products of 2557-13-3, the main research area is aryl acetophenone preparation; methyl benzoate Weinreb amide toluene benzylic aroylation.

Chemoselective deprotonative functionalization of benzylic C-H bonds is challenging, because the arene ring contains multiple aromatic C(sp2)-H bonds, which can be competitively deprotonated and lead to selectivity issues. Recently it was found that bimetallic [MN(SiMe3)2 M = Li, Na]/Cs+ combinations exhibit excellent benzylic selectivity. Herein, is reported the first deprotonative addition of toluenes to Weinreb amides mediated by LiN(SiMe3)2/CsF for the synthesis of a diverse array of 2-arylacetophenones. Surprisingly, simple Me benzoates also react with toluenes under similar conditions to form 2-arylacetophenones without double addition to give tertiary alc. products. This finding greatly increases the practicality and impact of this chem. Some challenging substrates with respect to benzylic deprotonations, such as fluoro and methoxy substituted toluenes, are selectively transformed to 2-aryl acetophenones. The value of benzylic deprotonation of 3-fluorotoluene is demonstrated by the synthesis of a key intermediate in the preparation of Polmacoxib.

Journal of Organic Chemistry published new progress about Acetophenones Role: SPN (Synthetic Preparation), PREP (Preparation) (2-aryl). 2557-13-3 belongs to class esters-buliding-blocks, and the molecular formula is C9H7F3O2, Related Products of 2557-13-3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Nikitas, Nikolaos F.; Triandafillidi, Ierasia; Kokotos, Christoforos G. published the artcile< Photo-organocatalytic synthesis of acetals from aldehydes>, Electric Literature of 34637-22-4, the main research area is aldehyde alc thioxanthenone catalyst photochem acetalization green chem; acetal preparation.

A mild and green photo-organocatalytic protocol for the highly efficient acetalization of aldehydes were developed. Utilizing thioxanthenone as the photocatalyst and inexpensive household lamps as the light source, a variety of aromatic and aliphatic aldehydes were converted into acyclic and cyclic acetals in high yields. The reaction mechanism was extensively studied.

Green Chemistry published new progress about Acetalization (photochem.). 34637-22-4 belongs to class esters-buliding-blocks, and the molecular formula is C11H15NO3, Electric Literature of 34637-22-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Liu, Bin; Thayumanavan, S. published the artcile< Substituent Effects on the pH Sensitivity of Acetals and Ketals and Their Correlation with Encapsulation Stability in Polymeric Nanogels>, Recommanded Product: Perfluorophenyl acrylate, the main research area is pH sensitivity acetal ketal encapsulation stability polymeric nanogel.

The effect of structural variations in acetal- and ketal-based linkers upon their degradation kinetics is studied through the design, synthesis, and study of six series of mols., comprising a total of 18 different mols. Through this systematic study, the structural fine-tuning of the linkers allows access to variations in kinetics of degradation of >6 orders of magnitude. Hammett correlations show that the ρ value for the hydrolysis of benzylidene acetals is ∼-4.06, which is comparable to an SN1-like process. There is a strong, developing pos. charge at the benzylic position in the transition state during the degradation of acetals. This pos. charged transition state is consistent with the relative degradation rates of acetals vs. ketals (correlated to stabilities of 1°, 2°, and 3° carboxonium ion type intermediates) and the observed effect of proximal electron-withdrawing groups upon the degradation rates. Following this, the authors studied whether the degradation kinetics study correlates with pH-sensitive variations in the host-guest characteristics of polymeric nanogels that contains these acetal or ketal moieties as crosslinking functionalities. Indeed, the trends observed in the small mol. degradation have clear correlations with the encapsulation stability of guest mols. within these polymeric nanogels. The implications of this fundamental study extend to a broad range of applications, well beyond the polymeric nanogel examples studied here.

Journal of the American Chemical Society published new progress about Acetals Role: PEP (Physical, Engineering or Chemical Process), PRP (Properties), RCT (Reactant), PROC (Process), RACT (Reactant or Reagent). 71195-85-2 belongs to class esters-buliding-blocks, and the molecular formula is C9H3F5O2, Recommanded Product: Perfluorophenyl acrylate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Van Driessche, Alexandra; Kocere, Agnese; Everaert, Hannelien; Nuhn, Lutz; Van Herck, Simon; Griffiths, Gareth; Fenaroli, Federico; De Geest, Bruno G. published the artcile< pH-Sensitive Hydrazone-Linked Doxorubicin Nanogels via Polymeric-Activated Ester Scaffolds: Synthesis, Assembly, and In Vitro and In Vivo Evaluation in Tumor-Bearing Zebrafish>, Formula: C9H3F5O2, the main research area is doxorubicin nanogel antitumor hydrazone tumor.

Nanoparticle conjugation is a powerful method to reduce the side effects of anticancer agents such as doxorubicin by altering the pharmacokinetic profile of the drug. Nanoparticles can prolong the circulation time and could also promote enhanced accumulation in tumors, either passively via the enhanced permeability and retention effect or actively when decorated with targeting motifs. For the particular case of doxorubicin, the hydrazone-based conjugation chem. is popular but commonly involves laborious chem. transformation steps. Here, we report on a straightforward route for the synthesis of hydrazone-based doxorubicin-polymer conjugates starting from a polymeric-activated ester scaffold onto which doxorubicin-reactive hydrazide moieties are introduced by simple treatment with hydrazine. Using block copolymers composed of a hydrophobic reactive ester block, we demonstrate a simple route to assemble core-crosslinked doxorubicin-loaded nanoparticles. The latter largely retain their bioactivity in vitro. In a zebrafish embryo “”premurine”” in vivo model, we demonstrate a drastic reduction in the systemic toxicity of doxorubicin upon nanoparticle conjugation and also demonstrate enhanced tumor accumulation and tumor growth reduction

Chemistry of Materials published new progress about Antitumor agents. 71195-85-2 belongs to class esters-buliding-blocks, and the molecular formula is C9H3F5O2, Formula: C9H3F5O2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Woodfield, Peter A.; Zhu, Yicheng; Pei, Yiwen; Roth, Peter J. published the artcile< Hydrophobically Modified Sulfobetaine Copolymers with Tunable Aqueous UCST through Postpolymerization Modification of Poly(pentafluorophenyl acrylate)>, SDS of cas: 71195-85-2, the main research area is hydrophobic pendant sulfobetaine copolymer postpolymn modification aqueous solution UCST.

Polysulfobetaines, polymers carrying highly polar zwitterionic side chains, present a promising research field by virtue of their antifouling properties, hemocompatibility, and stimulus-responsive behavior. However, limited synthetic approaches exist to produce sulfobetaine copolymers comprising hydrophobic components. Postpolymn. modification of an activated ester precursor, poly-(pentafluorophenyl acrylate), employing a zwitterionic amine, 3-((3-aminopropyl)-dimethylammonio)-propane-1-sulfonate, ADPS, is presented as a novel, 1-step synthetic concept toward sulfobetaine (co)-polymers. Modifications were performed in homogeneous solution using propylene carbonate as solvent with mixtures of ADPS and pentylamine, benzylamine, and dodecylamine producing well-defined statistical acrylamido sulfobetaine copolymers containing hydrophobic pentyl, benzyl, or dodecylacrylamide comonomers with well-controllable molar composition as evidenced by NMR and FTIR spectroscopy and size exclusion chromatog. This synthetic strategy was exploited to study, for the first time, the influence of hydrophobic modification on the upper critical solution temperature (UCST) of sulfobetaine copolymers in aqueous solution Surprisingly, incorporation of pentyl groups increases solubility over a wide composition range, whereas benzyl groups decreased solubility, an effect attributed to different entropic and enthalpic contributions of both functional groups. While UCST transitions of polysulfobetaines are typically limited to higher molar mass samples, incorporation of 0-65 mol.% of benzyl groups into copolymers with molar masses 25.5-34.5 kg/mol enabled sharp, reversible transitions 6-82° in solutions containing ≤76 mM NaCl, as observed by optical transmittance and dynamic light scattering. Both synthesis and systematic UCST increase of sulfobetaine copolymers presented here are expected to expand the scope and applicability of these smart materials.

Macromolecules (Washington, DC, United States) published new progress about Cloud point. 71195-85-2 belongs to class esters-buliding-blocks, and the molecular formula is C9H3F5O2, SDS of cas: 71195-85-2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Pokprasert, Adisak; Theato, Patrick; Chirachanchai, Suwabun published the artcile< Proton donor/acceptor copolymer brushes on sulfonated poly(ether ether ketone) membrane: An approach to construct efficient proton transfer pathway in polymer electrolyte membrane fuel cell>, Recommanded Product: Perfluorophenyl acrylate, the main research area is sulfonated poly ether ketone membrane proton transfer fuel cell.

Proton transfer in polymer electrolyte membrane is an essential mechanism in polymer electrolyte membrane fuel cell (PEMFC). The development of PEM mostly relies on polymer modification with proton conductive species followed by membrane casting. This brings in the random existence of conductive species in the membrane to result in a limit of conductivity The present work proposes an alignment of conductive species, i.e., proton donor and acceptor polymer chains, on the membrane through the surface-initiated polymerization so that the proton transfer proceeds effectively and continuously. The grafting of poly(acrylic acid) (Poly(AA) and/or poly(benzimidazole acrylamide) (Poly(BImAm)) onto sulfonated poly(ether ether ketone) membrane (SPEEK) enables the polymer brush decoration on the SPEEK surface. Among various types of copolymer architecture, the statistical copolymer, i.e. SPEEK-Poly(AA63-stat-BImAm26), shows the most significant proton conductivity The present work demonstrates a simple approach to modify the surface of PEMFC membrane with proton donor/acceptor for proton conductivity enhancement.

Polymer published new progress about Activation energy. 71195-85-2 belongs to class esters-buliding-blocks, and the molecular formula is C9H3F5O2, Recommanded Product: Perfluorophenyl acrylate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Hendrick, Charles E.; Jorgensen, Jeff R.; Chaudhry, Charu; Strambeanu, Iulia I.; Brazeau, Jean-Francois; Schiffer, Jamie; Shi, Zhicai; Venable, Jennifer D.; Wolkenberg, Scott E. published the artcile< Direct-to-Biology Accelerates PROTAC Synthesis and the Evaluation of Linker Effects on Permeability and Degradation>, Reference of 287114-25-4, the main research area is proteolysis targeting chimera preparation linker effect.

A platform to accelerate optimization of proteolysis targeting chimeras (PROTACs) had been developed using a direct-to-biol. (D2B) approach with a focus on linker effects. A large number of linker analogs-varying length, polarity, and rigidity-were rapidly prepared and characterized in four cell-based assays by streamlining time-consuming steps in synthesis and purification The expansive data set informs on linker structure activity relationships for in-cell E3 ligase target engagement, degradation, permeability, and cell toxicity. Unexpected aspects of linker SAR were discovered, consistent with literature reports on “”linkerol.””, and the method dramatically speeds up empirical optimization. Physicochem. property trends emerged, and the platform had the potential to rapidly expand training sets for more complex prediction models. In-depth validation studies were carried out and confirm the D2B platform was a valuable tool to accelerate PROTAC design-make-test cycles.

ACS Medicinal Chemistry Letters published new progress about Chemical library. 287114-25-4 belongs to class esters-buliding-blocks, and the molecular formula is C12H22N2O2, Reference of 287114-25-4.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhao, Hui; Gu, Weiyin; Thielke, Michael W.; Sterner, Elizabeth; Tsai, Tsunghan; Russell, Thomas P.; Coughlin, E. Bryan; Theato, Patrick published the artcile< Functionalized Nanoporous Thin Films and Fibers from Photocleavable Block Copolymers Featuring Activated Esters>, Application In Synthesis of 71195-85-2, the main research area is nanoporous thin film RAFT polymerization contact angle.

A series of poly(pentafluorophenyl (methyl)acrylates)-block-poly(ethylene oxide) with o-nitrobenzyl ester photocleavable junctions (PPFP(M)A-hv-PEO) were synthesized by RAFT polymerization The block copolymers were used to fabricate thin films and fibers by spin-coating and electrospinning, resp. After solvent annealing, UV exposure, and washing with methanol/water to remove the minor PEO block, nanoporous structures were obtained. Both the porous thin films and fibers remained reactive to amine substitution of the pentafluorophenyl esters under mild conditions, which was confirmed by XPS, fluorescence confocal microscopy, FT-IR, and contact angle measurements.

Macromolecules (Washington, DC, United States) published new progress about Azide-alkyne 1,3-dipolar cycloaddition reaction. 71195-85-2 belongs to class esters-buliding-blocks, and the molecular formula is C9H3F5O2, Application In Synthesis of 71195-85-2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics