Effects of Knot Tightness at the Molecular Level

Research output: Contribution to journalArticle

  • External authors:
  • Liang Zhang
  • Jean-Francois Lemonnier
  • Angela Acocella
  • Matteo Calvaresi
  • Francesco Zerbetto


Three 819 knots in closed-loop strands of different lengths (approximately 20, 23 and 26 nm) were used to experimentally assess the consequences of knot tightness at the molecular level. Through the use of 1H nuclear magnetic resonance (NMR), diffusion ordered spectroscopy (DOSY), circular dichroism (CD), collision induced dissociation mass spectrometry (CID-MS) and molecular dynamics (MD) simulations on the different sized knots, we find that the structure, dynamics and reactivity of the molecular chains are dramatically affected by the tightness of the knotting. The tautness of entanglement causes differences in conformation, enhances the expression of topological chirality, weakens covalent bonds, inhibits decomplexation events and changes absorption properties. Understanding the effects of tightening nanoscale knots may usefully inform the design of knotted and entangled molecular materials.

Bibliographical metadata

Original languageEnglish
JournalProceedings of the National Academy of Sciences
Early online date25 Jan 2019
Publication statusPublished - 2019

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