Fig. 7: Potential energy of demethylation C–C coupling reaction using stationary point and ab initio molecular dynamics calculations.

a Potential energy as a function of the distance (d₀) between the two positive charges on the carbonyl carbon atoms, with other degrees of freedom fixed at the equilibrium geometry, where d₁ is the effective radius of the reaction cross-section of the two R1 cations, and d₂ is C–C bond length. The potential energy at d₀ = 2.4 Å exceeds the energy of the C–C bond (~3.4 eV). b Interatomic distances and potential energy as a function of reaction time for one typical trajectory in Fig. 6b. (Note: Green curve represents the trend of the internuclear distance (Å) between the two carbonyl carbon atoms of sodiated acetone and sodiated acetone with bond forming. Blue curve represents the trend of the internuclear distance (Å) between the carbonyl carbon and methyl carbon in detaching CH₃⁺ and P4. Red curve represents the reaction potential energy. The variation fluctuations in 0–200 fs and 300-400 fs are caused by vibrations of molecules, while the drastic changes in 200−300 fs are due to the occurrence of chemical reactions).