In this work, we study the reaction mechanism of the tricarbonylchromium complex haptotropic rearrangementbetween two six-membered rings arranged like in naphthalene of four polycyclic aromatic hydrocarbons (PAHs).It has been found that the reaction mechanism of this haptotropic migration can either occur in a single stepor stepwise depending on the interaction between the orbitals of the Cr(CO)3 and the PAH fragments. Ourresults show that the size of the cyclic system favors the metal migration whereas the curvature of the organicsubstrate tends to slow down the rearrangement. We discuss the key factors that help to explain this behaviorthrough orbital and energy decomposition analysis.