Reexamination of 1,4-Hydride Exchange within the η⁵-Naphthalenyl Complex [Mn(η⁵-C₁₀H₉)(CO)₃] Establishes an Exchange Rate Intermediate between Those in the Cyclohexadienyl and Anthracenyl Analogues

Magnetization transfer experiments establish that the eta(5)-naphthalenyl complex [Mn(eta(5)-C10H9)(CO)(3)] participates in a 1,4-hydride shift reaction that involves exchange of the endo proton with the proton para to this position. Dynamic NMR studies establish that Delta G(double dagger) for this exchange is 21.0 kcal/mol at 298 K, intermediate between the previously reported exchange barriers of 34 kcal/mol in the benzene-derived complex [Mn(eta(5)-C6D6H)(CO)(3)] and 14.6 kcal/mol for the anthracene-derived complex [Mn(eta(5)-C14H11)(CO)(3)].