Mechanical Unfolding and Thermal Refolding of Single-Chain Nanoparticles Using Ligand-Metal Bonds

Avishai Levy, Roi Feinstein, Charles E. Diesendruck

Research output: Contribution to journalArticlepeer-review

Abstract

Covalent macromolecules tend to fragment under mechanical stress through the mechanochemical scission of covalent bonds in the backbone. However, linear polymers that have been intramolecularly collapsed by covalent bonds show greater mechanochemical stability compared to other thermoplastics. Here, rhodium-πbonds are used for intramolecular collapse in order to show that mechanical stress can be removed from the polymer backbone and focused on weaker intramolecular cross-links, leading to polymer unfolding instead of mechanochemical events at the backbone. Moreover, given rhodium-πbonds form spontaneously, by changing the time interval between ultrasound pulses, we demonstrate that entropic spring effects can lead to polymer refolding and reformation of the previously cleaved metal-ligand bonds, effectively repairing the intramolecular noncovalent cross-links. These findings provide the first example of an intramolecular repairing mechanism in synthetic molecules in solution, allowing for restoration of chemical bonds after mechanochemical events.

Original languageAmerican English
Pages (from-to)7256-7260
Number of pages5
JournalJournal of the American Chemical Society
Volume141
Issue number18
DOIs
StatePublished - 24 Apr 2019

All Science Journal Classification (ASJC) codes

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry

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