Structural and Mechanistic Aspects of Copper Catalyzed Atom Transfer Radical Polymerization

Abstract

During the past decade, atom transfer radical polymerization (ATRP) has had a tremendous impact on the synthesis of macromolecules with well-defined compositions, architectures, and functionalities. Structural features of copper(I) and copper(II) complexes with bidentate, tridentate, tetradentate, and multidentate nitrogen-based ligands commonly utilized in ATRP are reviewed and discussed. Additionally, recent advances in mechanistic understanding of copper-mediated ATRP are outlined.

Syntheses and Structures of Closely Related Copper(I) Complexes of Tridentate (2-Pyridylmethyl)imine and (2-Pyridylmethyl)amine Ligands and Their Use in Mediating Atom Transfer Radical Polymerizations

“…In addition, isolation of the halide-capped dormant polymers permits use of these products as macroinitiators for the syntheses of block copolymers. Since the original publications, catalysts based on a number of metals have been reported, including systems with titanium, iron, ruthenium, rhodium, nickel, palladium, and copper. ,, In each case, halide exchange between the metal and the growing polymer chain results in a formal oxidation state change at the metal center. The criteria for an efficient ATRP catalyst thus include the ability of the metal complex to undergo a reversible one-electron redox process at a suitable potential and allow for facile halogen atom transfer.…”