The acid-base character of interactions between xenon and selected carboxylic and sulfonic acids

- Main factors of 129Xe chemical shift of Xe-acid-solvent solutions were found.
- Contributions from H-bonding contacts to Xe depend on pKa of acids and solvents.
- Opposite shielding responses due to Xe-CH3 and Xe-CF3 contacts were found.

Interactions of Xe atoms with RCO2H and RSO3H (R = CH3 and CF3) acids in different solvents are examined by analysis of 129Xe chemical shifts extrapolated to zero solvent concentration. Obtained results are very sensitive to the Xe contacts with the methyl and trifluoromethyl groups as well as with the carboxylic and sulfonic groups of different acidity. The acid-base character of these acid-Xe interactions is considered.

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