Light-atom anomaly

{
  "id": "MLC-T-CHM-006585",
  "term": "Light-atom anomaly",
  "field": "Chemistry",
  "definition": "A dynamical effect in a reaction A + B-C giving A-B + C in which the transferred atom A, such as hydrogen, is much lighter than B and C. The light atom reaches bonding distance of B before C moves away, so the product A-B forms with little vibrational excitation, and the reaction energy is released mainly through repulsion between the product A-B and the departing C, appearing as translational energy of the products. The effect depends on the masses of the three atoms, not on isotopic substitution, so it is not a kinetic isotope effect.",
  "subject": "Physical and Biophysical Chemistry",
  "references": [
    "PAC, 1996, 68, 149. 'A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)' on page 171 (https://doi.org/10.1351/pac199668010149)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/light-atom-anomaly/"
}