New findings in the arene chemistry of the 3d transition metals

Abstract

This article surveys some new organometallic chemistry with the bicyclic aromatic hydrocarbon naphthalene. Aspects to be covered include the synthesis and properties of mononuclear complexes having 2-, 4- or 6-bonded naphthalene ligands. Examples of complexes of the latter type are CpM(6-C10H8) (M = Cr, V), which because of the lability of the arene ligands (naphthalene ligand effect) are valuable sources of CpM fragments. Also reported are the synthesis and structures of a series of homo- and heterodinuclear complexes in which the bicyclic arene functions as a bridging ligand. Finally, the two-step preparation of CpFe(5-C10H8-H) and CpFe (5-C10H8-D) starting from ferrocene is presented. These compounds, which can be regarded as a naphthalene molecule hydro- or deuterometallated by CpFe-H or CpFe-D fragments, undergo the reiro-hydro(deutero)metallation very easily when reacted with suitable substrates, liberating naphthalene. Thus, unlike the parent compound CpFe (5-C6H6-H), these two benzocyclohexadienyl iron(II) complexes are ready sources of CpFe fragments with metal-H or metal-D bonds. © 1990 De Gruyter