Document Type

Journal Article

Department/ Unit

Institute of Computational and Theoretical Studies

Abstract

© the Owner Societies 2016. Recently, a muscle-like organometallic polymer has been successfully synthesized using Fe2+ as a linker atom. The polymer exhibits acid-base controllable muscle-like expansion and contraction on the micrometer scale. Further development could be facilitated by revealing the polymerization mechanism and by searching for optimal linker atoms. In this work, we have examined possible equilibrium and intermediate polymer structures, which consist of [c2]daisy chains linked by divalent transition metal ions (Sc2+, Ti2+, Fe2+, Co2+, Ni2+ or Zn2+) with various hexa-coordination arrangements, based on calculations using density functional theory. We find that the metal linkers in polymers are weaker in acid than in base due to excess positive charges on the polymer, leading to their thermodynamical instability or even decomposition. This can explain the experimental difficulty in improving the degree of polymerization for metal-linked polymers. We also find that the polymers with either Fe2+ or Co2+ are the most favorable, with the latter extending 1.4% longer than with the former. Since Fe2+ has been confirmed experimentally to be a successful linker, Co2+ would function equally well and thus could be used as an alternative choice for polymerization.

Publication Year

2015

Journal Title

Physical Chemistry Chemical Physics

Volume number

10

Issue number

18

Publisher

Public Library of Science

First Page (page number)

7419

Last Page (page number)

7426

Referreed

1

DOI

10.1039/c5cp07772a

ISSN (print)

14639076

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