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Probing Instantaneous Single-Molecule Chirality in the Planar Ground State of Formic Acid
D Tsitsonis1, M Kircher1, N M Novikovskiy2
1Goethe-Universität Frankfurt, Institut für Kernphysik, Max-von-Laue-Straße 1, 60438 Frankfurt am Main, Germany.
Physical Review Letters
|February 16, 2026
Summary
Individual formic acid molecules are chiral, even in their ground state. This chirality is revealed by tracking photoelectrons and molecular fragments, showing consistent handedness for each molecule.
Area of Science:
- Molecular physics
- Quantum chemistry
- Chirality studies
Background:
- Formic acid possesses a planar equilibrium structure, suggesting achirality.
- Molecular chirality is typically associated with non-planar structures.
- Understanding molecular handedness is crucial in chemistry and biology.
Purpose of the Study:
- To experimentally determine if individual formic acid molecules exhibit chirality.
- To investigate the relationship between molecular structure, vibrational states, and chirality.
- To explore the generalizability of observed chirality in prochiral molecules.
Main Methods:
- Ionization of the Carbon 1s shell of formic acid molecules.
- Coincidence detection of photoelectrons and resulting charged fragments.
- Photoelectron diffraction imaging for structural determination.
- Coulomb explosion imaging for structural determination.
Main Results:
- Experimental evidence confirms individual formic acid molecules are chiral in their vibronic ground state.
- Both photoelectron diffraction and Coulomb explosion imaging consistently determined the same molecular handedness.
- The observed chirality in individual molecules contrasts with the molecule's achiral average structure.
Conclusions:
- Individual molecules can exhibit chirality even with a planar equilibrium structure.
- Three-dimensional zero-point nuclear delocalization in the vibrational ground state leads to molecular chirality.
- This phenomenon is applicable to other prochiral molecules, highlighting a fundamental aspect of molecular structure.
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