Issue 8, 2022

Effect of halogen and solvent on iron-catalyzed atom transfer radical polymerization

Abstract

Efficient transfer of halogen atoms is essential for controlling the growth of polymers in atom transfer radical polymerization (ATRP). The nature of halogens may influence the efficiency of the halogen atom transfer during the activation and deactivation processes. The effect of halogens can be associated with the C–X bond dissociation energy and the affinity of the halogens/halides to the transition metal catalyst. In this paper, we study the effect of halogens (Br vs. Cl) and reaction media in iron-catalyzed ATRP in the presence of halide anions as ligands. In Br-based initiating systems, polymerization of methacrylate monomers was well-controlled whereas Cl-based initiating systems provided limited control over the polymerization. The high affinity of the Cl atom to the iron catalyst renders it less efficient for fast deactivation of growing chains, resulting in polymers with molecular weights higher than predetermined by Δ[M]/[RX]o and with high dispersities. Conversely, Br can be exchanged with higher efficiency and hence provided good control over polymerization. Decreasing the polarity of the reaction medium improved the polymerization control. Polymerizations using ppm levels of the iron catalyst in acetonitrile (a more polar solvent) yielded polymers with larger dispersity values due to the slow rate of deactivation as opposed to the less polar solvent anisole, which afforded well-controlled polymers with dispersity <1.2.

Graphical abstract: Effect of halogen and solvent on iron-catalyzed atom transfer radical polymerization

Supplementary files

Article information

Article type
Paper
Submitted
01 ዲሴም 2021
Accepted
12 ጃንዩ 2022
First published
21 ጃንዩ 2022

Polym. Chem., 2022,13, 1059-1066

Author version available

Effect of halogen and solvent on iron-catalyzed atom transfer radical polymerization

S. Dadashi-Silab, K. Kim, F. Lorandi, D. J. Schild, M. Fantin and K. Matyjaszewski, Polym. Chem., 2022, 13, 1059 DOI: 10.1039/D1PY01601F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements