NMR investigation into the dynamic behaviour of a novel C2-symmetric macrocyclic ligand

Magn Reson Chem. 2005 Apr;43(4):321-5. doi: 10.1002/mrc.1539.

Abstract

The variable-temperature (1)H NMR spectra of a tosylated triazacyclononane are reported. The spectra show a dynamic process which is assigned to hindered rotation about the amide-like N--S bonds, and a value for the free energy of activation for the rotations is derived, DeltaG* = 50.2 kJ mol(-1) at 273 K. Steric and electronic factors which influence the barrier are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Heterocyclic Compounds / chemistry
  • Kinetics
  • Ligands
  • Macrocyclic Compounds / chemistry*
  • Magnetic Resonance Spectroscopy / methods*
  • Magnetic Resonance Spectroscopy / standards*
  • Molecular Conformation
  • Protons
  • Reference Standards
  • Stereoisomerism
  • Temperature

Substances

  • Heterocyclic Compounds
  • Ligands
  • Macrocyclic Compounds
  • Protons
  • 1,4,7-triazacyclononane