Nonradical Light-Controlled Polymerization of Styrene and Vinyl Ethers Catalyzed by an Iridium–Palladium Photocatalyst

Abstract

A visible-light-sensitive Ir–Pd photocatalyst is effective for coordination copolymerization of styrene and vinyl ethers. The catalyst drastically accelerates styrene polymerization under visible light irradiation and allows sequence-controlled copolymerization of styrene and vinyl ethers by appropriate switching of the irradiation sequence. The reaction rates of the monomers under irradiated and nonirradiated conditions were compared. Mechanistic studies suggested that the reactions proceeded via a nonradical coordination–insertion mechanism.

Olefins and Vinyl Polar Monomers: Bridging the Gap for Next Generation Materials

“…Photochemical manipulation of ac atalyst offers af acile stimulus which can afford control over the catalystsr eactivity.I nagaki and co-workers reported the photo-controlled homo-and copolymerizations of styrenic monomers mediated by ab ichromophoric cationic iridium-palladium complex. [106] Theauthors illustrated that upon exposure to visible light irradiation (420 nm), the electronic structure of the Ir-Pd catalyst facilitated the coordination-insertion copolymerization of styrene with vinyl ethers such as 2,2,2-trifluoroethyl vinyl ether (TFEVE) and pentafluorophenylbenzyl vinyl ether (PTPBVE). In the dark, the Pd II species catalyzed only vinyl ether polymerization via ac oordination-insertion mechanism.…”

Mixed Polymer Brushes for “Smart” Surfaces

“…While the groundwork has been laid by a body of impressive work from previous researchers, there remains room for improvement to help pave the road for MPBs to transition into industrial application and scale-up. For example, recent developments in polymer brushes synthesis, including oxygen tolerance [60,81], metal-free polymerization [82], and external regulation [81,83,84,[174][175][176][177][178][179][180] have the potential to make MPB fabrication more user friendly than ever before. Newly described orthogonal approaches in solution will increase synthetic precision: in contrast to sequential SI-FRP/SI-RDRP, orthogonal polymerization techniques and "click" reactions do not compete for the same initiating sites and improve control over grafting ratios.…”

Controlled Synthesis of Block Copolymers by Mechanistic Transformation from Atom Transfer Radical Polymerization to Iniferter Process

“…In recent years, there has been tremendous interest in developing new controlled/living polymerization (CLP) methods, involving almost all modes of polymerization processes …”

“…In recent years, there has been tremendous interest in developing new controlled/living polymerization (CLP) methods, involving almost all modes of polymerization processes. [25][26][27][28][29][30][31][32][33] Following the invention of living anionic polymerization by Szwarc in 1956, [34] there has been an increasing attention to develop new CLP techniques because of their usefulness to access various macro molecular architectures with designable molecular weights, low polydispersity, and beneficially preserved end-functionalities. A recent example of controlled/ living polymerization process is related to the polymerization of vinyl ethers by photoinduced radical oxidation addition deactivation (PROAD) processes.…”