PreprintCC BY-NC-NDChemRxiv
Proton Solvation Thermochemistry: A Temperature-Resolved Calibration from Ammonium Acids
Abstract
Chemical reactions involving protonation are ubiquitous in nature, yet their accurate description using static quantum-chemical methods remains challenging. Here, we derive a temperature-resolved aqueous free energy of H+ (G◦,aq H+ ) by combining experimental pKa data for 12 ammonium acids over 293–333 K with a high-level composite quantum-chemical protocol based on LNO-CCSD(T)/CBS energies, CPCM solvation, and conformational thermochemistry. Thermodynamic analysis gives G◦,aq H+ = −270.0 kcal/mol at 298 K, within 0.3 kcal/mol of the canonical literature value (Tissandier et al., 1998). The fitted parameters are robust under cross-validation, and validation on an independent set of 18 acids yields a mean absolute error of 0.70 pKa units.
Related
- Spatially resolved system-level calibration for high-fidelity complex-amplitude modulation using a phase-only spatial light modulator
- Feature calibration-enabled fine spatial resolution temperature demodulation with RDTS system
- Optical Calibration of a Frequency-Domain-Multiplexed X-Ray TES Microcalorimeter Array via Photon-Number-Resolved Statistics
- The Simons Observatory: Frequency-resolved beam calibration for the SO SATs with POLOCALC
- Demonstration of a cryogenic, switchable electron source for low-temperature detector calibration
BibTeX
@misc{jaradat2026proton,
title = {{Proton Solvation Thermochemistry: A Temperature-Resolved Calibration from Ammonium Acids}},
author = {Khaled Jaradat and Bence Balázs Mészáros and János Daru},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15009422/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009422/v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Proton Solvation Thermochemistry: A Temperature-Resolved Calibration from Ammonium Acids
AU - Khaled Jaradat
AU - Bence Balázs Mészáros
AU - János Daru
PY - 2026
DA - 2026/09/24
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009422/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009422/v1
AB - Chemical reactions involving protonation are ubiquitous in nature, yet their accurate description using static quantum-chemical methods remains challenging. Here, we derive a temperature-resolved aqueous free energy of H+ (G◦,aq H+ ) by combining experimental pKa data for 12 ammonium acids over 293–333 K with a high-level composite quantum-chemical protocol based on LNO-CCSD(T)/CBS energies, CPCM solvation, and conformational thermochemistry. Thermodynamic analysis gives G◦,aq H+ = −270.0 kcal/mol at 298 K, within 0.3 kcal/mol of the canonical literature value (Tissandier et al., 1998). The fitted parameters are robust under cross-validation, and validation on an independent set of 18 acids yields a mean absolute error of 0.70 pKa units.
ER -