# Are heterolytic dissociations barrier-less or do they have an activation energy?

When a bond is broken into ionic fragments, and I'm specifically thinking about organometallic or coordination chemistry, the two products carry opposite charges and the potential energy curve should, in my humble opinion, be attractive everywhere (at every point where the distance is larger than its equilibrium value).

Does this mean that the dissociation of a compound like ferrocene into $\ce{FeCp+}$ and $\ce{Cp-}$ (in the gas phase) occurs without a barrier?

• What is IMHO? If the potential energy is a curve, does it not already imply an energy barrier? – stochastic13 Jan 11 '16 at 15:14
• Yeah, what you say implies exactly the opposite. – Mithoron Jan 11 '16 at 15:33
• IMHO = "in my humble opinion". The fact that the potential energy curve is attractive everywhere just means that the energy rises the further you pull the two ions apart. A barrier implies that the energy rises up to the transition state and then falls again as you approach the product valley. You could re-phrase my question as: Is there a transition state? – Ben Winston Jan 11 '16 at 20:48