Reaction of Me2Si(C9H7)Cl with 1 equiv of Li2C2B10H10 gave, after hydrolysis, the new versatile ligand Me2Si(C9H7)(C2B10H11) (1). 1 can be conveniently converted into the monoanion [Me2Si(C9H6)(C2B10H11)]-(2) and the dianion [Me2Si(C9H6)(C2B10H10)]2-(3) by treatment with 1 equiv or excess amounts of NaH, respectively. Treatment of SmI2 with 2 in THF gave the unexpected redox product [η5:η6-Me2Si(C9H6)(C2B10H11)]Sm(THF)2 (4). Reaction of SmI2 with 1 equiv of 3 in THF, followed by reaction with 2, gave the unexpected C-H bond reduction product [{η5:σ-Me2Si(C9H6)(C2B10H10)}2Sm][Na(THF)6] (5). In contrast, reaction of YbI2 with 1 or 2 equiv of 2 afforded [{η5-Me2Si(C9H6)(C2B10H11)}Yb(σ-I)(THF)2]2 (6) or [η5-Me2Si(C9H6)(C2B10H11)]2Yb(THF)2 (7), respectively. Treatment of YbI2 with 1 equiv of 3 in THF gave [η5:σ-Me2Si(C9H6)(C2B10H10)]Yb(THF)3 (8), which is the first mixed-ligand organolanthanide(II) complex containing both Ln-C ð and ó bonds to be reported. 8 can also be prepared from the reaction of 6 with excess NaH in THF. Reaction of 8 with 1 equiv of 2 in THF yielded [η5-Me2Si(C9H6)(C2B10H11)]Yb(THF)[(μ-η5):σ-Me2Si(C9H6)(C2B10H10)]Na-(THF)3 (9), which can also be prepared by reaction of 7 with 1 equiv of NaH in THF. These new complexes have been fully characterized by 1H, 13C, and 11B NMR, IR spectroscopy, and elemental analyses. The molecular structures of 4, 5, 8, and 9 have been further confirmed by single-crystal X-ray analyses.

Summary: Reaction of Me2Si(C9H7)(C2B10H11) with 4 equiv of NaNH2 in dry THF, followed by treatment with 1 equiv of LnCl3, gave unprecedented tetranuclear clusters of the general formula [{(η5-μ2-C9H6SiMe2NH)-Ln}2(μ3-Cl)(THF)]2(í4-NH)âTHF (Ln) Gd (1), Er (2)) in moderate yield. Their molecular structures have been confirmed by single-crystal X-ray analyses, which represent the first organometallic clusters containing a central μ4-imido group.

Reaction of Me2Si(Me2NCH2CH2C9H6)Cl with 1 equiv of t-BuNHLi yielded Me2Si(Me2-NCH2CH2C9H6)(t-BuNH) (1). Treatment of Me2NCH2CH2C9H7 with 1 equiv of n-BuLi, followed by reaction with an excess of Me3SiCl, produced Me2NCH2CH2C9H6SiMe3 (2) in 9% yield. Interaction of YbCl3 with 3 equiv of (Me3Si)2NLi in THF, after workup, produced the tetracoordinate ytterbium(Ⅲ) amide [(Me3Si)2N]3YbⅢ　(μ-Cl)Li(THF)3 (3) in 85% yield. Treatment of 3 with 2 equiv of 1 gave the ytterbium(Ⅱ) complex [è5:è1-Me2Si(Me2NCH2-CH2C9H5)(t-BuNH)]2YbⅡ (4) in 58% yield via a reductive reaction. To get some insight into the reaction, several reactions were initiated to study the effects of the t-BuNH group, silyl group, and N,N-dimethylaminoethyl group of the indene compounds, effects of coordinate ClLi(THF)3 in 3, and temperature effect on the reductive reaction. Treatment of 3 with-equiv of 2 afforded (η5:η1-Me2NCH2CH2C9H5SiMe3)2YbII (5) in 52% yield. Interaction of 3 with 2 equiv of Me2NCH2CH2C9H7 produced a ytterbium(Ⅱ) complex (η5:η1-Me2NCH2-CH2C9H6)2YbⅡ (6) in 63% yield. Treatment of the ytterbium(Ⅲ) complex [(Me3Si)2N]3YbIII with 2 equiv of Me2NCH2CH2C9H7 also afforded the ytterbium(Ⅱ) complex (η5:η1-Me2NCH2-CH2C9H6)2YbII (6) in 62% yield, which provides an alternate method for the preparation of 6. Treatment of 3 with 2 equiv of indene(C9H8) produced the ytterbium(Ⅲ) complex (η5-C9H7)2YbIIIN(SiMe3)2 (7). Treatment of 3 with 1 equiv of 1,2-bis(indenyl)ethane also produced the ytterbium(Ⅲ) complex meso-[ethylenebis(è5-indenyl)ytterbiumⅢ bis(trimethylsily)amide ((EBI)YbIIIN(SiMe3)2) (8). All the compounds were fully characterized by spectroscopic methods and elemental analyses. Complexes 3, 4, 5, 6, and 8 were additionally characterized by a single-crystal X-ray diffraction study. The formation pathway for the ytterbium(Ⅱ) complexes is proposed. The study showed that ytterbuim(Ⅱ) complexes 4, 5, and 6 can function as single-component MMA polymerization catalysts with good activity.

New ether-functionalized carboranyl-indenyl hybrid ligands were prepared. They can prevent lanthanocene chlorides from ligand redistribution reactions and offer samarium(Ⅱ) complexes unusual reactivities. Treatment of Me2SiCl(C9H6CH2CH2OMe) with 1 equiv of Li2C2B10H10 in toluene/Et2O afforded the monolithium salt [Me2Si(C9H5CH2CH2OMe)-(C2B10H11)]Li(OEt2) (2). Interaction of 2 with 1 equiv of n-BuLi in Et2O produced the dilithium salt [Me2Si(C9H5CH2CH2OMe)(C2B10H10)]Li2(OEt2)2 (3). Reaction of 3 with 1 equiv of LnCl3 at room temperature gave the complex salts of general formula [{[è5:ó-Me2Si(C9H5CH2CH2-OMe)(C2B10H10)]Ln(THF)(μ-Cl)3Ln[η5:η1:η-e2Si(C9H5CH2CH2OMe)(C2B10H10)]}2{Li(THF)}]-[Li(THF)4] (Ln) Y (4), Yb (5)). Upon heating, 5 was converted into [η5:η1:η-Me2Si(C9H5-CH2CH2OMe)(C2B10H10)]Yb(THF)(μ-Cl)2Yb[η5:η1:η-Me2Si(C9H5CH2CH2OMe)(C2B10H10)] (6) by eliminating LiCl. Treatment of 4 or 5 with 2 equiv of group 1 metal amides gave organorare-earth amide complexes [è5:è1:ó-Me2Si(C9H5CH2CH2OMe)(C2B10H10)]Y(NHC6H3-2,5-tBu2)-(μ-Cl)Li(THF)3 (8) or [η5:η1:η-Me2Si(C9H5CH2CH2OMe)(C2B10H10)]Yb(NHC6H3-2,6-iPr2)(í-Cl)Li(THF)3 (9). An equimolar reaction of SmI2 with 3 in THF generated, after addition of LiCl, [{[è5:η-Me2Si(C9H5CH2CH2OMe)(C2B10H10)]2Sm}{Li(THF)}]n (10) and [{η5:η1:η6-Me2-Si(C9H5CH2CH2OMe)(C2B10H10)Sm}2(í-Cl)][Li(THF)4] (11). In sharp contrast, a less reactive YbI2 reacted with 3 in THF, producing only salt metathesis product [η5:η1:η-Me2Si(C9H5-CH2CH2OMe)(C2B10H10)]Yb(DME)(THF) (12). 12 reacted with 1 equiv of 3 to give the ionic complex {[(μ-η5:η2):η1:η-Me2Si(C9H5CH2CH2OMe)(C2B10H10)]2Yb}{Li(THF)2}2 (13). All complexes were characterized by various spectroscopic techniques and elemental analyses. The structures of 5, 6, and 8-13 were further confirmed by single-crystal X-ray analyses.

The interaction of methoxyethyl functionalized indene compounds (C9H6-1-R-3-CH2CH2OMe, R=t-BuNHSiMe(1), Me3Si (2), H (3)) with [(Me3Si)2N]3Ln(μ-Cl)Li(THF)3 (Ln=Yb (4), Eu (5)) produced a series of new ytterbium (Ⅱ) and europium (Ⅱ) complexes via tandem silylamine elimination/homolysis of the Ln-N (Ln=Yb, Eu) bond.Treatment of the lanthanide (Ⅱ) amides [(Me3Si)2N]3Ln(μ-Cl)Li(THF)3 (Ln=Yb (4), Eu (5) with 2 equiv. of 1, 2and 3, respectively, produced, after workup, the ytterbium (Ⅱ) complexes [η5:η1-Me2Si(MeOCH2CH2C9H5)(NHBu-t)]2-YbII (6), (η5:η1-MeOCH2CH2C9H5SiMe3)2YbII (7), (η5:η1-MeOCH2CH2C9H6)2YbII (8) and the correspondingeuropium (Ⅱ) complexes [η5:η1-Me2Si(MeOCH2CH2C9H5)(NHBu-t)]2EuII (9), (η5:η1-MeOCH2CH2C9H5SiMe3)2EuII (10) and (η5:η1-MeOCH2CH2C9H6)2EuII (11) in moderate to good yield. In contrast, interaction of the corresponding indene compounds 1, 2 or 3 with the lanthanide amides [(Me3Si)2N]3Ln (Ln = Yb, Eu) was not observed, while addition of 0.5 equiv. of anhydrous LiCl to the corresponding reaction mixture produced, after workup, the corresponding ytterbium (Ⅱ) or europium (Ⅱ) complexes. All the new compounds were fully characterized by spectroscopic and elemental analyses. The structures of complexes 7, 9 and 10 were determined by single-crystal X-ray analyses. The catalytic activity of all the ytterbium (Ⅱ) and europium (Ⅱ) complexes on MMA polymerization was examined. It was found that all the ytterbium (Ⅱ) and europium (Ⅱ) complexes can function as single-component MMA polymerization catalysts. The temperature, solvent and ligand effects on the catalytic activity were studied.