Anionic Polymerization Mechanism of Acrylonitrile Trimer Anions : Key Branching Point between Cyclization and Chain Propagation

Journal of Physical Chemistry A Volume 116 Issue 30 Page 7937-7942 published_at 2012-08-02
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Title ( eng )
Anionic Polymerization Mechanism of Acrylonitrile Trimer Anions : Key Branching Point between Cyclization and Chain Propagation
Creator
Ohshimo Keijiro
Ohno Koichi
Source Title
Journal of Physical Chemistry A
Volume 116
Issue 30
Start Page 7937
End Page 7942
Abstract
A cluster anion of vinyl compounds in the gaseous phase has served as one of the simplest microscopic models of the initial stages of anionic polymerization. Herein, we describe our investigations into the initial stage mechanisms of anionic polymerization of acrylonitrile (AN; CH2=CHCN) trimer anions. While the cyclic oligomer is found in mass and photoelectron spectroscopic studies of (AN)3-, only the chain oligomer is found in the infrared photodissociation (IRPD) spectrum of Ar-tagged (AN)3-. Based on the calculated polymerization pathway of (AN)3-, we consider that the chain oligomers are the reaction intermediates in the cyclization of (AN)3-. The rotational isomerization of the (AN)3- chain oligomer is found to be the bottleneck in the cyclization of (AN)3-. To form the (AN)4- chain oligomer by chain propagation, the addition of an AN molecule to (AN)3- should occur prior to the rotational isomerization. We conclude that the rotational isomerization in the (AN)3- chain oligomer is the key branching point between cyclization (termination) or chain propagation in the anionic polymerization.
Keywords
Intracluster reaction
cluster anions
infrared spectroscopy
reaction pathway
Descriptions
This is a preprint of an article published by American Chemical Society in Journal of Physical Chemistry A, 2012, available online: http://pubs.acs.org/doi/abs/10.1021/jp305291r.
NDC
Chemistry [ 430 ]
Language
eng
Resource Type journal article
Publisher
American Chemical Society
Date of Issued 2012-08-02
Rights
Copyright (c) 2012 American Chemical Society
Publish Type Author’s Original
Access Rights open access
Source Identifier
[ISSN] 1089-5639
[DOI] 10.1021/jp305291r
[DOI] http://dx.doi.org/10.1021/jp305291r isVersionOf
[PMID] 22775348