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Updated: Jan 12, 2026

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Revisiting Iodine: From Chain Transfer Agent to Halogen Bonding and Nonmetallic Lewis Acid Catalysis
1Department State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, 30 Puzhu Road South, Nanjing 211816, China.
Abstract:
Iodine has long been recognized as a chain transfer agent in radical polymerizations, enabling controlled synthesis through reversible C-I bond exchange. Recent advancements have expanded its role as a nonmetallic Lewis acid, driven by halogen bonding and three-center-four-electron (3c4e) interactions. This Viewpoint examines the evolution of iodine-mediated radical polymerization and highlights the role of 3c4e interactions in supramolecular chemistry and polymer synthesis, with a particular focus on ring-opening polymerizations (ROP) and CO2-based copolymerizations. These developments bridge radical chemistry with halogen bonding, offering environmentally friendly, metal-free alternatives to traditional methods. We explore how iodine catalysis contributes to sustainable polymer synthesis and propose strategies for advancing high-performance, sustainable polymerization systems.
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