Promoting halogen-bonding catalyzed living radical polymerization through ion-pair strain

Abstract

Discovering efficient catalysts is highly desired in expanding the application of halogen-bonding catalysis. We herein report our findings on applying triaminocyclopropenium (TAC) iodides as highly potent catalysts for halogen-bonding catalyzed...

Reversed Controlled Polymerization (RCP): Depolymerization from Well-Defined Polymers to Monomers

“…Recently, Liu and co-workers demonstrated the use of triaminocyclopropenium (TACP) iodides as an ion-pair catalyst in halogen-bonding catalyzed living radical polymerization . The iodine anion of the TACP iodide activates iodine-terminated polymers, resulting in the generation of propagating radicals.…”

“…GPC traces obtained from the samples: before reaction (black line); reacted at 120 °C for 24 h with TACP-I as catalyst (red line); reacted at 150 °C for 24 h with TACP-I as catalyst (blue line). Figure adapted with permission from Royal Society of Chemistry from ref , copyright 2022; permission conveyed through Copyright Clearance Center, Inc.…”

“…Recently, Liu and co-workers demonstrated the use of triaminocyclopropenium (TACP) iodides as an ion-pair catalyst in halogen-bonding catalyzed living radical polymerization. 68 The iodine anion of the TACP iodide activates iodine-terminated polymers, resulting in the generation of propagating radicals. In addition to the reported polymerizations, the authors also showed that the same catalytic system can be employed for the depolymerization of PMMA with tetraglyme as a solvent, at 3.2 mM polymer concentration, at 120 °C for 24 h. Control experiments in the absence of catalyst showed no monomer generation; however, depolymerization was detected when 100 equiv of TACP catalyst were employed.…”

Light-accelerated depolymerization catalyzed by Eosin Y

“…[9][10][11] In order to achieve an efficient unzipping of the polymer chains, high endgroup fidelity has to first be ensured during the respective polymerizations as minimal, if any, depolymerization can be observed when these end-groups are removed. 12,13 As such, the vast majority of investigated depolymerizable polymers were synthesized by either reversible addition-fragmentation chaintransfer (RAFT) polymerization or atom transfer radical polymerization (ATRP), [12][13][14][15][16][17][18][19] two of the most widely used RDRP techniques. [20][21][22][23] In seminal independent works by the groups of Gramlich 18 and Raus, 24 they showed that the depolymerization of bottlebrush polymers synthesized by either RAFT or ATRP was possible at relatively low temperatures (70 °C and 90 °C respectively).…”

“…This is shown by the fact that minimal depolymerization was observed when the end-groups were removed. 12,13 As such, the vast majority of investigated depolymerizable polymers were synthesized by either reversible addition–fragmentation chain-transfer (RAFT) polymerization or atom transfer radical polymerization (ATRP), 12–19 two of the most widely used RDRP techniques. 20–23…”