Cp`2LnR(THF) (Cp`=C5H4CH3) reacted with phenyl isocyanate to form the PhNCO insertion products [Cp

The synthesis, structures, and reactivity of new lanthanocene complexes incorporating amidinate ligand [tBuN.C(nBu).NtBu] are described. Treatment of Cp2LnnBu (Ln) Er (1), Y (2), Gd (3)) with N,N

Reactions of Cp3Ln (Cp) C5H5; Ln) Ho, Dy, Yb, Sm) with 2 equiv of HPzMe2 (HPzMe2=3,5-dimethylpyrazole) in THF at room temperature yield complexes CpLn(PzMe2)2 [Ln=Ho (1), Dy (2)], Cp2Yb(PzMe2)(HPzMe2) (3), and Sm(PzMe2)3 (5), respectively, indicating that the number of cyclopentadienyl groups liberated from a Cp3Ln moiety is largely influenced by the size of the lanthanide ion. Reaction of Cp3Er and 1 equiv of HPzMe2 under the same conditions gave Cp2Er(PzMe2)(THF) (4). The structures of 3 and 4 were determined by X-ray diffraction. In both complexes the central metal ions are coordinated to four ligands in a typical "bent metallocene" geometry. Complexes 1 and 2 react with dimethylsilicone grease to give the corresponding Me2SiO insertion products [CpLn(PzMe2)(OSiMe2PzMe2)]2 [Ln=Ho (6), Dy (7)]. The results of the investigation show that the insertion of dimethylsilicone into the Ln-N bond is only possible for the monocyclopentadienyl-type organolanthanide pyrazolates. X-ray diffraction reveals complex 6 to be a centrosymmetric dimer in which each holmium atom is coordinated to one cyclopentadienyl group, two bridging oxygen atoms, and three nitrogen atoms, two from the chelating PzMe2 ligand and one from the bridging 3,5-dimethylpyrazolyl siloxide ligand to form a distorted octahedron.

The reaction of (C5H5)YCl2(THF)3 with LiNiPr2 and subsequently with 2 equiv of N,N

Treatment of [Cp2Ln(μ-SEt)]2 with PhRCdCdO gives dimeric complexes [Cp2Ln(μ-η1:η2-OC(SEt)dCPhR)]2 [R=Ph, Ln=Yb (1), Er (2), Sm (3), Y (4); R=Et, Ln=Er (5)], which represent the first example of ketene insertion into a metal-sulfur bond and provide an efficient method for the synthesis of organolanthanides with a β-thiolate-substituted enolate ligand. It is found that an excess of ketene does not affect the nature of the final complexes, with only a single insertion being observed. All these complexes are characterized by elemental analysis and spectroscopic properties. The structures of complexes 1âC6H5CH3, 2•C6H5CH3, and 5âTHF are determined through single-crystal X-ray diffraction analysis.