Term: protofugality
https://doi.org/10.1351/goldbook.08197

Definition:
Special case of nucleofugality, describing the relative rates of transfer of a proton (more generally: hydron) from a series of Brønsted acids \(\ce{H-X}\) to a common Brønsted base.

Note: This term has the advantage over the commonly used "kinetic acidity" that philicity and fugality are associated with kinetics, while acidity and basicity are associated with thermodynamics.

Link: 

Source: PAC, 2022, 94, 353. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)' on page 487 (https://doi.org/10.1515/pac-2018-1010)

Citation: 'protofugality' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.08197

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