General method for determination of the activation, deactivation, and initiation rate constants in transition metal-catalyzed atom transfer radical processes

Tomislav Pintauer; Peng Zhou; Krzysztof Matyjaszewski

doi:10.1021/ja0265097

General method for determination of the activation, deactivation, and initiation rate constants in transition metal-catalyzed atom transfer radical processes

J Am Chem Soc. 2002 Jul 17;124(28):8196-7. doi: 10.1021/ja0265097.

Authors

Tomislav Pintauer¹, Peng Zhou, Krzysztof Matyjaszewski

Affiliation

¹ Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA.

PMID: 12105893
DOI: 10.1021/ja0265097

Abstract

A general method for the determination of the activation (ka), deactivation (kd), and initiation (ki) rate constants in atom transfer radical processes is reported. The method involves the monomer trapping techniques and the analytical solution of the persistent radical effect. For tert-butyl 2-bromopropionate, using ATRP catalyst [CuI(dNbpy)2][Br] and methyl methacrylate in CH3CN at 22 degrees C, the values of ka, kd, and ki were determined to be (9.4 +/- 0.6) x 10-3 M-1 s-1, (8.5 +/- 1.2) x 106 M-1 s-1 and (5.5 +/- 0.9) x 104 M-1 s-1, respectively. The determined initiation rate constant was in good agreement with the literature value (6.0 x 104 M-1 s-1), confirming the validity of the proposed approach. For methyl 2-bromopropionate, under the same conditions, ka, kd, and ki values were found to be (26 +/- 5.9) x 10-3 M-1 s-1, (29 +/- 7.3) x 106 M-1 s-1, and (5.7 +/- 1.6) x 104 M-1 s-1, respectively.