Kinetics of Amine-Bis(phenolate) Iron-Mediated ATRP Up to High Pressure

Hendrik Schroeder, Michael Buback, Michael P. Shaver

Research output: Contribution to journalArticlepeer-review

Abstract

Atom-transfer radical polymerization (ATRP) of styrene catalyzed by chloro-substituted amine-bis(phenolate)iron complexes was investigated via online vis/NIR spectroscopy up to 6000 bar. Pressure significantly increases the rate of ATRP by enhancing both the equilibrium constant, K-ATRP, and the propagation rate coefficient, k(p). The observed negative reaction volume, Delta V-r(K-ATRP), is due to a stronger contraction of the ligand sphere for the Lewis-acidic Fe-III complex compared to the Fe-II complex. Despite the enormous rate enhancement of ATRP, narrow molar mass distributions may be obtained even at very high pressure and thus very high rates.

Original languageEnglish
Pages (from-to)6114-6120
Number of pages7
JournalMacromolecules
Volume48
Issue number17
DOIs
Publication statusPublished - 8 Sep 2015

Keywords

  • TRANSFER RADICAL POLYMERIZATION
  • ACTIVATION-DEACTIVATION EQUILIBRIUM
  • PROPAGATION RATE COEFFICIENT
  • METAL SPIN-STATE
  • ATOM-TRANSFER
  • METHYL-METHACRYLATE
  • TERMINATION KINETICS
  • RATE CONSTANTS
  • IRON(III) COMPLEXES
  • RAFT-POLYMERIZATION

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