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Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
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Asymmetric [N-I-N]+ halonium complexes in solution?
Daniel von der Heiden1, Kari Rissanen, Máté Erdélyi
1Department of Chemistry - BMC, Uppsala University, SE-751 23 Uppsala, Sweden. mate.erdelyi@kemi.uu.se.
Chemical Communications (Cambridge, England)
|November 4, 2020
Summary
Iodine(I) complexes show a preference for more basic pyridines, with ligand exchange favoring asymmetric systems due to entropy. This research aids in understanding halonium ion halogen bonds.
Area of Science:
- Coordination Chemistry
- Supramolecular Chemistry
- Physical Chemistry
Background:
- Halonium ions, particularly iodine(I) complexes, are crucial in supramolecular chemistry and synthetic applications.
- Understanding the solution equilibria and ligand exchange dynamics of these complexes is key to their effective utilization.
Purpose of the Study:
- To investigate the solution equilibria of [bis(pyridine)iodine(i)]+ complexes.
- To determine the factors influencing ligand exchange and complex formation, including ligand basicity and environmental conditions.
- To explore the driving forces behind the formation of asymmetric systems.
Main Methods:
- Electrospray Ionization Mass Spectrometry (ESI-MS) for analyzing complex formation in solution.
- Nuclear Magnetic Resonance (NMR) spectroscopy to study ligand exchange and equilibria.
Main Results:
- Iodine(I) exhibits a clear preference for coordinating with more basic pyridine ligands.
- Ligand exchange in mixtures of symmetric [bis(pyridine)iodine(i)]+ complexes statistically favors the formation of asymmetric systems.
- An entropic driving force predominantly influences the preference for asymmetric complex formation.
Conclusions:
- The basicity of pyridine ligands significantly impacts the stability and formation of iodine(I) complexes.
- Entropic factors play a critical role in directing ligand exchange towards asymmetric structures.
- These findings provide valuable insights for advancing research and applications involving halonium ions and halogen bonding.
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