Isotope Effects on Chemical Shifts in the Study of Hydrogen Bonds in Small Molecules

This review is giving a short introduction to the techniques used to investigate isotope effects on NMR chemical shifts. The review is discussing how isotope effects on chemical shifts can be used to elucidate the importance of either intra- or intermolecular hydrogen bonding in ionic liquids, of ammonium ions in a confined space, how isotope effects can help define dimers, trimers, etc., how isotope effects can lead to structural parameters such as distances and give information about ion pairing. Tautomerism is by advantage investigated by isotope effects on chemical shifts both in symmetric and asymmetric systems. The relationship between hydrogen bond energies and two-bond deuterium isotope effects on chemical shifts is described. Finally, theoretical calculations to obtain isotope effects on chemical shifts are looked into.

Automated summary

This review provides a brief introduction to the techniques used for investigating isotope effects on NMR chemical shifts. It discusses the importance of isotope effects in elucidating intra- or intermolecular hydrogen bonding, ammonium ions in confined spaces, defining dimers, trimers, etc., and providing information about ion pairing. The review also explores the relationship between hydrogen bond energies and two-bond deuterium isotope effects on chemical shifts, as well as theoretical calculations for obtaining these effects.