Synthetic and Structural Study on Orthometallated Ferrocene Complexes: Non-Planar Metallabenzene and Five-Membered Metallacycle Complexes with Closed Os3 Triangles

Abstract

Thermolysis of (Z)-1-ferrocenyltelluro-1-ferrocenyl-4-ferrocenyl-1-buten-3-yne with [Os3(CO)12] in toluene gave two new clusters: non-planar six-membered metallacycle complex [Os3H(CO)7(µ3-Te){η1:η1:η2:η2-FcCCC(H)(Fc)2}] (1, Fc = ferrocenyl) and five-membered cyclometallated ring complex [Os3(CO)7(µ3-Te){η1:η1:η3-FcC(H)C(H)CC(Fc)2}] (2). Compounds 1 and 2 may be thought to form by orthometallation of ferrocene with a closed Os3 triangle by intramolecular rearrangement of atoms within the cluster complexes. Typically the formation of a non-planar metallabenzene such as 1 may involve the orthometallation of another aromatic ring. Also, conversion of 1 to 2 shows the initial step required for alkene hydrogenation by a tellurium-bridged triosmium cluster. Both compounds were characterized by IR and 1H NMR spectroscopy, and their structures established by single-crystal XRD. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim