Reversible Generation of a Carbon-Centered Radical from Alkyl Iodide Using Organic Salts and Their Application as Organic Catalysts in Living Radical Polymerization

Hexamethylphosphoramide as a highly reactive catalyst for the reversible-deactivation radical polymerization of MMA with an in situ formed alkyl iodide initiator

A novel and highly efficient organic catalyst for the reversible-deactivation radical polymerization (RDRP) of methyl methacrylate with anin situformed alkyl iodide initiator.

Self-condensing reversible complexation-mediated copolymerization for highly branched polymers with in situ formed inimers

In this work, reversible complexation-mediated polymerization (RCMP) was modified to suit self-condensing vinyl polymerization (SCVP) aimed at the synthesis of highly branched polymers.

Step Transfer-Addition and Radical-Termination (START) Polymerization of α,ω-Unconjugated Dienes under Irradiation of Blue LED Light

A new polymerization method, termed as step transfer-addition and radical-termination, is developed for the step-growth radical polymerization of α,ω-unconjugated dienes under irradiation of visible light at room temperature (25 °C) for the first time. α,ω-Diiodoperfluoroalkane monomers (signified as A) are added onto α,ω-unconjugated dienes (signified as B) alternatively and efficiently with the generation of perfluorocarbon-containing alternating copolymers (AB)_n . Based on the combined analyses of polymerization kinetics and NMR spectra (¹ H and ¹⁹ F), the mechanism of the novel polymerization method, including the side reaction, is proposed. This novel polymerization method provides a new strategy not only for the step-growth radical polymerization of α,ω-unconjugated dienes but also for the construction of high molecular weight perfluorocarbon-containing alternating copolymers.

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The procedure is performed under an inert atmosphere using air- and water-exclusion techniques. The outcome of the polymerization is affected by the ratios of monomer, initiator, and catalyst used as well as the reaction concentration, solvent, and nature of the light source. Temporal control over the polymerization can be exercised by turning the visible light source off and on. Low dispersities of the resultant polymers as well as the ability to chain-extend to form block copolymers suggest control over the polymerization, while chain end-group analysis provides evidence supporting an atom-transfer radical polymerization mechanism.

Organocatalyzed atom transfer radical polymerization driven by visible light

Atom transfer radical polymerization (ATRP) has become one of the most implemented methods for polymer synthesis, owing to impressive control over polymer composition and associated properties. However, contamination of the polymer by the metal catalyst remains a major limitation. Organic ATRP photoredox catalysts have been sought to address this difficult challenge but have not achieved the precision performance of metal catalysts. Here, we introduce diaryl dihydrophenazines, identified through computationally directed discovery, as a class of strongly reducing photoredox catalysts. These catalysts achieve high initiator efficiencies through activation by visible light to synthesize polymers with tunable molecular weights and low dispersities.

PMDETA as an efficient catalyst for bulk reversible complexation mediated polymerization (RCMP) in the absence of additional metal salts and deoxygenation

PMDETA was used as a commercial and efficient catalyst for reversible complexation mediated polymerization (RCMP) without deoxygenation in bulk, which could potentially allow the more facile preparation, post-treatment and storage.

Redox Active Compounds in Controlled Radical Polymerization and Dye-Sensitized Solar Cells: Mutual Solutions to Disparate Problems

Controlled radical polymerization (CRP) and dye-sensitized solar cells (DSSCs) are two fields of research that at an initial glance appear to have little in common. However, despite their obvious differences, both in application and in scientific nature, a closer look reveals a striking similarity between many of the compounds widely used as control agents in radical polymerization and as redox couples in dye-sensitized solar cells. Herein, we review the various redox active compounds used and examine the characteristics that give them the ability to perform this dual function. In addition we explore the advances in the understanding of the structural features that enhance their activity in both CRP and DSSCs. It is hoped that such a comparison will be conducive to improving process performance in both fields.

Photoinduced Metal-Free Atom Transfer Radical Polymerization of Acrylonitrile

Photoinduced metal-free atom transfer radical polymerization has been successfully extended to the synthesis of polyacrylonitrile (PAN) with predictable molecular weights and low dispersities. This was achieved using phenothiazine derivatives as photoredox catalysts, which activate dormant alkyl bromides to reversibly form propagating radicals. Both ¹H NMR spectroscopy and chain-end extension polymerization show highly preserved Br chain-end functionality in the synthesized PAN.

Tertiary amine catalyzed photo-induced controlled radical polymerization of methacrylates

A novel tertiary amine catalyst and trithiocarbonate synergistic photo-induced controlled radical polymerization of methacrylates has been realized under mild UV irradiation, yielding polymethacrylates with low molecular weight distributions and excellent end-group fidelity.

Macromolecular engineering by atom transfer radical polymerization

This Perspective presents recent advances in macromolecular engineering enabled by ATRP. They include the fundamental mechanistic and synthetic features of ATRP with emphasis on various catalytic/initiation systems that use parts-per-million concentrations of Cu catalysts and can be run in environmentally friendly media, e.g., water. The roles of the major components of ATRP--monomers, initiators, catalysts, and various additives--are explained, and their reactivity and structure are correlated. The effects of media and external stimuli on polymerization rates and control are presented. Some examples of precisely controlled elements of macromolecular architecture, such as chain uniformity, composition, topology, and functionality, are discussed. Syntheses of polymers with complex architecture, various hybrids, and bioconjugates are illustrated. Examples of current and forthcoming applications of ATRP are covered. Future challenges and perspectives for macromolecular engineering by ATRP are discussed.

Nitroxide-mediated surfactant-free emulsion copolymerization of methyl methacrylate and styrene using poly(2-(diethyl)aminoethyl methacrylate-co-styrene) as a stimuli-responsive macroalkoxyamine

The SG1-mediated copolymerization of 2-(diethyl)aminoethyl methacrylate (DEAEMA) and a small percentage of styrene (S) was performed.