Jong KNCV Café Amsterdam
The quantum chemical nature of hydrogen bonds demystifies misconceptions
Aan het einde van de avond vindt er een chemisch georiënteerde pubquiz plaats, georganiseerd door het Amsterdams Chemisch Dispuut.
Spreker: Lucas de Azevedo Santos
Datum: 25 november 2025
Tijd: 19.00u - 22.00u
Locatie: Brainwave, Amsterdam
Deelname is gratis voor KNCV-leden. Niet-leden betalen €5.
Bij inschrijving ontvang je 2 gratis drankjes en wij zorgen voor de hapjes.
Summary
In this work, we present a quantum chemical description of hydrogen bonding and clarify misconceptions arising from its classical mechanical interpretation. Hydrogen bonding is a crucial chemical interaction across many areas of chemistry, including reactivity and catalysis, and fundamental physicochemical properties such as boiling points. While classically described as a Coulombic attraction between protonic Y–Hδ+ donors and negatively charged acceptors, a recent proposal has suggested extending hydrogen bonding to include hydridic Y–Hδ− donors, following observations such as the Me3Si–Hδ−•••ICN complex. However, the quantum mechanical interpretation of hydrogen bonds, based on Kohn–Sham molecular orbital (KS-MO) theory, challenges this proposal and other fundamental misconceptions.[1] Quantum mechanics shows that hydridic hydrogen bonds cannot exist because of the Pauli exclusion principle. An increased overlap between same-spin occupied orbitals not only weakens hydrogen bonds but completely prevents their formation in the case of hydridic Y–Hδ− fragments.
References
[1] L. de Azevedo Santos, P. Vermeeren, F. Matthias Bickelhaupt, C. Fonseca Guerra, J. Am. Chem. Soc. 2024, 146, 25701.
