Mixed cyclopentadienyl-naphthalene complexes of rare-earth elements: Mono- and binuclear derivatives. Molecular structure of (eta(5)-C5H5)YC10H8(DME)

Reaction of CpLnCl(2)(THF)(3) (Ln = Y, Gd, Er, and Tm) with sodium naphthalenide in 1,2-dimethoxyethane (DME) gives mononuclear complexes CpLnC(10)H(8)(DME). Binuclear complexes (CpLn)(2)C10H8(THF)(4) (Ln = Sm and Yb) containing the Ln atoms in the oxidation state +2 are formed in similar reactions of Sm and Yb complexes. The structure of CpYC(10)H(8)(DME) was determined by the X-ray diffraction method. The coordinated naphthalene ring linked to the Y atom is nonplanar: it is bent by an angle 26.1 degrees over the C(1)...C(4) line. The existence of two short, Y(1)-C(1) and Y(1)-C(4) (2.438(6) and 2.452(6) Angstrom), and two long, Y(1)-C(2) and Y(1)-C(3) (2.599(7) and 2.598(7) Angstrom), Y-C(C10H8) bonds testifies to the 2 eta(1):eta(2)-interaction of the Y atom with the naphthalene dianion. The same yttrium complex in a mixture with Cp(3)Y is formed in the reaction of Cp(1)YCl with sodium naphthalenide.