Reactivity oscillation in the heavy–light–heavy Cl + CH ₄ reaction

Significance The hydrogen atom transfer reactions are ubiquitous in chemical and biological processes; therefore, heavy–light–heavy (HLH) reactions are of great practical importance and chemically interesting. This joint experimental and theoretical study not only shows the existence of HLH reactivity oscillation in a bimolecular reaction, but also rationalizes why such an HLH oscillation can be observed in polyatomic reactions, but not in triatomic reactions. In addition, our study represents an important progress in the dynamics study of chemical reaction with quantum differential cross-sections calculated accurately and good agreement with experiment obtained for a chemical reaction involving more than four atoms.