On the structure and fluxionality of mononuclear complexes of naphthalene: A DFT investigation of (naphthalene)MCp (M = Sc, V, Mn, Fe, Ni) and related complexes

The coordination modes of naphthalene to a MCp metal moiety has been investigated in the series of first-row transition metals. Depending on the electron-richness of M, the coordination modes of naphthalene in the ground state configuration can be η2, η4 or η6. The η3 or η10 coordination mode are also possible in high-energy minima which are predicted to be reaction intermediates in haptotropic migration mechanisms interconverting degenerate ground state structures. Except for the M = Sc case, all the inter-ring haptotropic exchanges occur through a transition state or intermediate in which the metal moiety is bonded in an exocyclic way to the naphthalene ligand.