Acid-base actuation of [c2]daisy chains. Academic Article uri icon

abstract

  • A versatile synthetic strategy, which was conceived and employed to prepare doubly threaded, bistable [c2]daisy chain compounds, is described. Propargyl and 1-pentenyl groups have been grafted onto the stoppers of [c2]daisy chain molecules obtained using a template-directed synthetic protocol. Such [c2]daisy chain molecules undergo reversible extension and contraction upon treatment with acid and base, respectively. The dialkyne-functionalized [c2]daisy chain (AA) was subjected to an [AA+BB] type polymerization with an appropriate diazide (BB) to afford a linear, mechanically interlocked, main-chain polymer. The macromolecular properties of this polymer were characterized by chronocoulometry, size exclusion chromatography, and static light-scattering analysis. The acid-base switching properties of both the monomers and the polymer have been studied in solution, using (1)H NMR spectroscopy, UV/vis absorption spectroscopy, and cyclic voltammetry. The experimental results demonstrate that the functionalized [c2]daisy chains, along with their polymeric derivatives, undergo quantitative, efficient, and fully reversible switching processes in solution. Kinetics measurements demonstrate that the acid/base-promoted extension/contraction movements of the polymeric [c2]daisy chain are actually faster than those of its monomeric counterpart. These observations open the door to correlated molecular motions and to changes in material properties.

published proceedings

  • J Am Chem Soc

altmetric score

  • 3

author list (cited authors)

  • Fang, L., Hmadeh, M., Wu, J., Olson, M. A., Spruell, J. M., Trabolsi, A., ... Stoddart, J. F.

citation count

  • 174

complete list of authors

  • Fang, Lei||Hmadeh, Mohamad||Wu, Jishan||Olson, Mark A||Spruell, Jason M||Trabolsi, Ali||Yang, Ying-Wei||Elhabiri, Mourad||Albrecht-Gary, Anne-Marie||Stoddart, J Fraser

publication date

  • May 2009