High Performance Redox Initiating Systems Based on the Interaction of Silane with Metal Complexes: A Unique Platform for the Preparation of Composites

Currently, Redox Initiating Systems (RISs) of Free Radical Polymerization (FRP) are mainly based on the interaction of aromatic amines with peroxides (e.g., dibenzoyl peroxide (BPO)) that can be both toxic and unstable. In the present work, we aim to replace these hazardous substances in new RIS that can be peroxide-free and amine-free. Our redox two components (2K) initiating system is based on diphenylsilane (DPS) as reducing agent combined with different metal complexes (Mn(acac)2, Cu(AAEMA)2 or Fe(acac)3) as oxidizing agents. For the new proposed RIS, an excellent reactivity is found for the polymerization of benchmark methacrylate monomers under mild conditions (redox polymerization done under air and at room temperature); remarkably, it is also possible to finely control the gel time. Different techniques (optical pyrometry, Real-Time FTIR spectroscopy, Cyclic Voltammetry and Electron Spin Resonance (ESR)) were used to follow the polymerization processes but also to shed some light on the new redox chemical mechanisms.

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Electron spin resonance spectroscopic detection in high-performance liquid chromatography: determination of metal complexes with radical-containing chelating reagents

The Analyst ◽

10.1039/an9891401337 ◽

1989 ◽

Vol 114 (10) ◽

pp. 1337 ◽

Cited By ~ 1

Author(s):

Yuri A. Zolotov ◽

Oleg M. Petrukhin ◽

Andrei R. Timerbaev ◽

Michail V. Evstiferov ◽

Valeri V. Salov ◽

...

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Electron Spin Resonance ◽

Metal Complexes ◽

Electron Spin ◽

High Performance ◽

Spin Resonance ◽

Chelating Reagents

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Room-Temperature, Base-Mediated Selective Synthesis of 2-(Arylamino)ethanols and 2-Aryloxyethanols

SynOpen ◽

10.1055/s-0039-1690334 ◽

2019 ◽

Vol 03 (04) ◽

pp. 124-137 ◽

Cited By ~ 2

Author(s):

Rahul B. Sonawane ◽

Swapnali R. Sonawane ◽

Nishant K. Rasal ◽

Sangeeta V. Jagtap

Keyword(s):

Functional Groups ◽

Aromatic Amines ◽

Room Temperature ◽

Alkyl Halide ◽

Selective Synthesis ◽

Formal Synthesis ◽

Mild Conditions ◽

Primary Aromatic Amines

A simple and efficient protocol for base-mediated selective synthesis of 2-(arylamino)ethanols from primary aromatic amines and 2-aryloxyethanols from phenols, promoted by K2CO3 has been achieved under mild conditions. Even in presence of excess alkyl halide, selective mono-N-alkylation has been achieved. Tolerance of a variety of functional groups is demonstrated by 15 examples of selective N-alkylation of aromatic amines and 19 examples of O-alkylation of phenols. The efficacy of the protocol is demonstrated by the formal synthesis of Ticlopidine®, Vildagliptin®, Quetiapine®, and Gemfibrozil®.

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Electron spin resonance of spin trapped radicals in γ-irradiated polycrystalline dipeptides. Chromatographic separation of radicals

Canadian Journal of Chemistry ◽

10.1139/v82-214 ◽

1982 ◽

Vol 60 (12) ◽

pp. 1480-1485 ◽

Cited By ~ 13

Author(s):

Keisuke Makino ◽

Peter Riesz

Keyword(s):

High Performance Liquid Chromatography ◽

Electron Spin Resonance ◽

Ring Opening ◽

High Performance ◽

Room Temperature ◽

Spin Trap ◽

Esr Spectra ◽

Spin Resonance ◽

Carboxyl Terminal ◽

Deamination Reaction

Polycrystalline dipeptides (glycyl-glycine, glycyl-L-valine, glycyl-L-leucine, L-alanyl-glycine, and L-prolyl-L-alanine) were γ-irradiated at room temperature in the absence of air. Subsequently they were dissolved in aqueous solutions containing 2-methyl-2-nitrosopropane as the spin trap. From the esr spectra of the nitroxide radicals separated by high-performance liquid chromatography, structural assignments of the radicals were made. For glycyl peptides, H-abstraction from the α-carbon atoms of the carboxyl terminal residues and from the side-chains were observed. For L-alanyl-glycine, H-abstraction from the glycyl residue and the formation of the deamination radical could be shown to occur. For L-prolyl-L-alanine, the ring opening (deamination) reaction, decarboxylation and H-abstraction from the C-terminal a-carbon were seen.

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Free Radical Photopolymerization and 3D Printing Using Newly Developed Dyes: Indane-1,3-Dione and 1H-Cyclopentanaphthalene-1,3-Dione Derivatives as Photoinitiators in Three-Component Systems

Catalysts ◽

10.3390/catal10040463 ◽

2020 ◽

Vol 10 (4) ◽

pp. 463 ◽

Cited By ~ 8

Author(s):

Ke Sun ◽

Corentin Pigot ◽

Hong Chen ◽

Malek Nechab ◽

Didier Gigmes ◽

...

Keyword(s):

Free Radical ◽

3D Printing ◽

High Performance ◽

Chemical Mechanisms ◽

Esr Spin Trapping ◽

Free Radical Photopolymerization ◽

Spin Resonance ◽

Component Systems ◽

Iodonium Salt ◽

First Time

The design of photoinitiating systems with excellent photochemical reactivities at 405nm LED is one of the obstacles to efficiently promote free radical polymerization in mild conditions (e.g., low light intensity, under air). Here, our actual search for new multicomponent photoinitiating systems at 405nm LED prompts us to develop new dyes based on push–pull structures. In the present paper, we chose two series of new dyes which possess indane-1,3-dione and 1H-cyclopenta naphthalene-1,3-dione groups as the electron-withdrawing groups, since they have the great potential to behave as sensitive and remarkable photoinitiators in vat photopolymerization/3D printing. When incorporated with a tertiary amine (ethyl dimethylaminobenzoate EDB, used as electron/hydrogen donor) and an iodonium salt (used as electron acceptor) as the three-component photoinitiating systems (PISs), and among a series of 21 dyes, 10 of them could efficiently promote the free radical photopolymerization of acrylates. Interestingly, steady state photolysis experiments revealed different behaviors of the dyes. Fluorescence experiments and free energy change calculations for redox processes were also carried out to investigate the relevant chemical mechanisms. Additionally, the formation of radicals from the investigated PISs was clearly observed by electron spin resonance (ESR) spin-trapping experiments. Finally, stereoscopic 3D patterns were successfully fabricated by the laser writing technique. In this work, the use of push–pull dyes based on the naphthalene scaffold as photoinitiators of polymerization is reported for the first time in a systematic study aiming at investigating the structure–performance relationship for irradiation carried out at 405 nm. By carefully selecting the electron donors used in the two series of push–pull dyes, novel and high-performance photoinitiating systems operating at 405 nm are thus proposed.

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Enantioselective Friedel - Crafts Reactions of Aromatic Amines with Ethyl Glyoxylate in Pyridinium-Based Ionic Liquids

Australian Journal of Chemistry ◽

10.1071/ch06221 ◽

2006 ◽

Vol 59 (7) ◽

pp. 468 ◽

Cited By ~ 5

Author(s):

Sanjay V. Malhotra ◽

Ying Xiao

Keyword(s):

Ionic Liquids ◽

Reaction Time ◽

Metal Complexes ◽

Reaction Temperature ◽

Aromatic Amines ◽

Reaction Parameters ◽

Chiral Catalysts ◽

Mild Conditions ◽

Solvent Systems ◽

High Yields

The Friedel–Crafts reactions of aromatic amines with ethyl glyoxylate in pyridinium-based ionic liquids (ILs) are investigated using 2,2′-dihydroxy-1,1′-binaphthyl (BINOL) metal complexes as chiral catalysts. Reaction parameters such as the catalyst–IL compositions, reactant compositions, reaction time, and reaction temperature are studied. High yields and excellent enantioselectivities are achieved under the relatively mild conditions. The ILs can also be recycled and reused as opposed to traditional solvent systems.

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New Pure Organic and Peroxide-Free Redox Initiating Systems for Polymerization in Mild Conditions

Polymers ◽

10.3390/polym13020301 ◽

2021 ◽

Vol 13 (2) ◽

pp. 301

Author(s):

Ahmad Arar ◽

Lilian Wisson ◽

Jacques Lalevée

Keyword(s):

Free Radical ◽

Thermal Imaging ◽

High Performance ◽

Room Temperature ◽

High Reactivity ◽

Light Activation ◽

Work Time ◽

Mild Conditions ◽

Full Control ◽

Iodonium Salt

Redox initiating systems (RISs) are highly worthwhile for polymerization in mild conditions (at room temperature—RT) without external thermal or light activation. With high performance redox initiating systems RIS, the free radical polymerization FRP can even be carried out under air and without inhibitors/stabilizers removal from the monomers/resins. However, efficient RISs are still based on peroxides or metal complexes. In this work, a pure organic and peroxide-free RIS is presented based on the interaction of a well-selected triarylamine derivative (T4epa) with iodonium salt used as reducing and oxidizing agents, respectively. The redox polymerization (Redox FRP) was followed through pyrometry and thermal imaging experiments. Remarkably, a full control of the work time as well as a high reactivity is observed for mild conditions.

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Cross-linked nonwoven fibers produced by room temperature cure blowing and in situ photopolymerization: 'Greener' approach to high performance nonwovens

10.1021/scimeetings.0c01646 ◽

2020 ◽

Author(s):

Aditya Banerji ◽

Kailong Jin ◽

Mahesh Mahanthappa ◽

Christopher J Ellison

Keyword(s):

High Performance ◽

Room Temperature ◽

Nonwoven Fibers

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SuFEx Activation with Ca(NTf2)2: A Unified Strategy to Access Sulfamides, Sulfamates and Sulfonamides from S(VI) Fluorides

10.26434/chemrxiv.12026811.v1 ◽

2020 ◽

Author(s):

Subham Mahapatra ◽

Cristian P. Woroch ◽

Todd W. Butler ◽

Sabrina N. Carneiro ◽

Sabrina C. Kwan ◽

...

Keyword(s):

Room Temperature ◽

Medicinal Chemistry ◽

Mild Conditions ◽

Broad Array

A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide, and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight the application of this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds.

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