Chapter 7. Competitive Equilibria in Atom Transfer Radical Polymerization

  1. Prof. Dr. Michael Buback4 and
  2. A. M. van Herk5
  1. Nicolay V. Tsarevsky1,
  2. Wade A. Braunecker1,
  3. Alberto Vacca2,
  4. Peter Gans3 and
  5. Krzysztof Matyjaszewski1

Published Online: 31 MAY 2007

DOI: 10.1002/9783527610860.ch7

Radical Polymerization: Kinetics and Mechanism, Volume 248

Radical Polymerization: Kinetics and Mechanism, Volume 248

How to Cite

Tsarevsky, N. V., Braunecker, W. A., Vacca, A., Gans, P. and Matyjaszewski, K. (2007) Competitive Equilibria in Atom Transfer Radical Polymerization, in Radical Polymerization: Kinetics and Mechanism, Volume 248 (eds M. Buback and A. M. van Herk), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany. doi: 10.1002/9783527610860.ch7

Editor Information

  1. 4

    Institute of Physical Chemistry, Georg-August-University Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany

  2. 5

    Laboratory for Polymer Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands

Author Information

  1. 1

    Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA

  2. 2

    Dipartimento di Chimica, Universita degli Studi di Firenze, Via della Lastruccia 3, I 50019, Sesto Fiorentino, Italy

  3. 3

    Protonic Software, Leeds LS15 0HD, U.K.

Publication History

  1. Published Online: 31 MAY 2007
  2. Published Print: 13 APR 2007

ISBN Information

Print ISBN: 9783527320561

Online ISBN: 9783527610860

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Keywords:

  • atom transfer radical polymerization;
  • catalysis;
  • complex stability;
  • competitive complexation;
  • electron transfer

Summary

With the recent development of new initiation techniques in atom transfer radical polymerization (ATRP) that allow catalysts to be employed at unprecedented low concentrations (∼10 ppm), a thorough understanding of competitive equilibria that can affect catalyst performance is becoming increasingly important. Such mechanistic considerations are discussed herein, including i) factors affecting the position of the ATRP equilibrium; ii) dissociation of the ATRP catalyst at high dilution and loss of deactivator due to halide dissociation; iii) conditional stability constants as related to competitive monomer, solvent, and reducing agent complexation as well as ligand selection with respect to protonation in acidic media; and iv) competitive equilibria involving electron transfer reactions, including the radical oxidation to carbocations or reduction to carbanions, radical coordination to the metal catalyst, and disproportionation of the Cu'-based ATRP activator.