Mass-independent isotope fractionation: quantum effect leading to a unusual isotope chemistry

P. Reinhardt,1 F. Robert2

1 Laboratoire de Chimie Théorique, Sorbonne Université and CNRS UMR7616, 4 place Jussieu, F-75252 Paris CEDEX 05, France 2 2 Institut Origine et Evolution (O & E), Muséum National d'Histoire Naturelle et Sorbonne Université, IMPMC-UMR 7590 CNRS, 57 rue Cuvier, 75005 Paris, France


Observed first for ozone, mass-independent isotope fractionations (enrichments or depletions) have been recorded as well for Mg and Ti isotopes, of orders of magnitude far beyond natural samples. The puzzling results may be traced back to the quantum-mechanical principle according to which in an isotope scattering identical isotopes behave not like classical particles. A simple model allows to obtain the effect from quasi-classical simulations, beyond differences in ZPEs or rotational selection rules. We will show results for the ozone chemistry, and interpret recent experiments on the other isotope systems from the essence of the ozone model.

  1. P. Reinhardt, F. Robert, On the mass-independent isotope fractionation in ozone, Chem.Phys.A, 513 (2018) 287-294.
  2. F Robert, P. Reinhardt, R Tartèse, Mass-Independent Fractionation of Titanium Isotopes, Chemical Physics, 540 (2021) 110970.