A further, simplified, model at the CCSD(T)/Def2-TZVPPD/SCRF=dichloromethane level was computed, the dissociation of Me-I + -C≡C -→ Me-I + C⩸C. A solvation model is essential, since the ionic reactant is expected to be substantially stabilized by solvation compared to the non-ionic reaction products. At this level of theory, the energy of C2 itself is computed to be too stable by ~4.6 kcal/mol. With this correction applied, the overall reaction free energy emerges as G298 +47.1 kcal/mol, again in the range 43-53 kcal/mol. The former value corresponds to a half-life of a unimolecular reaction (Eyring theory) of ~10 18 hours at 298K.