Document Type

Journal Article

Abstract

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

2016

Journal Title

Physical Chemistry Chemical Physics

Volume number

18

Issue number

10

Publisher

Royal Society of Chemistry

First Page (page number)

7419

Last Page (page number)

7426

Referreed

1

DOI

10.1039/C5CP07772A

ISSN (print)

14639084

Link to Publisher’s Edition

https://dx.doi.org/10.1039/C5CP07772A

Additional Files

JA-5059-28582_suppl.pdf (1562 kB)

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