Reaction of Me2Si(C5H5)Cl with 1 equiv of Li2C2B10H10 in toluene/ether at 0℃, after hydrolysis, gave Me2Si(C5H5)(C2B10H11) (1) in 79% isolated yield. 1 can be conveniently converted into the monoanion [Me2Si(C5H4)(C2B10H11)]Na (2), the dianion [Me2Si(C5H4)-(C2B10H10)]Li2 (3), and the trianion [Me2Si(C5H4)(C2B10H11)]K3 (4) by treatment with NaH, MeLi, and K metal in THF at room temperature, respectively. 2 reacted with 1 equiv of LnCl3 in THF to give [η5-Me2Si(C5H4)(C2B10H11)]LnCl2(THF)3 (Ln) Nd (5), Sm (6), Er (7), Yb (8)) in good yield. Treatment of LnCl3 with 2 equiv of 2 or reaction of [è5-Me2Si(C5H4)-(C2B10H11)]LnCl2(THF)3 with an equimolar amount of 2 in THF resulted in the isolation of [η5-Me2Si(C5H4)(C2B10H11)]2LnCl(THF)2 (Ln) Nd (9), Sm (10), Y (11), Gd (12), Yb (13)) in good yield. Interaction of 3 with LnCl3 in THF in a molar ratio of 1∶1 or 2∶1 or reaction of [η5-Me2Si(C5H4)(C2B10H11)]2LnCl(THF)2 with 2 equiv of MeLi in THF gave the same compounds [{η5:σ-Me2Si(C5H4)(C2B10H10)}2Ln][Li(THF)4] (Ln) Nd (14), Y (15), Er (16), Yb (17)). Treatment of NdCl3 with an equimolar amount of 4 in THF or reaction of [η5-Me2Si-(C5H4)(C2B10H11)]NdCl2(THF)3 with excess K metal in THF produced [η5:η6-Me2Si(C5H4)-(C2B10H11)]Nd(THF)2 (18). Under similar reaction conditions, however, interaction of LnCl3 (Ln) Sm, Yb) with 4 in THF afforded the organolanthanide(Ⅱ) compounds {[η5:η6-Me2Si-(C5H4)(C2B10H11)]LnII(THF)2}{K(THF)2} (Ln) Sm (20), Yb (21)). The Sm analogue of 18, [η5:η6-Me2Si(C5H4)(C2B10H11)]Sm(THF)2 (19), was prepared from an unprecedented redox reaction of SmI2 with 2 equiv of 2 in THF. Reaction of 19 with excess K metal in THF gave 20. Unlike the SmI2 case, interaction of YbI2 with 2 equiv of 2 in THF gave [η5-Me2Si(C5H4)-(C2B10H11)]2YbII(THF)2 (22). All of these compounds were characterized by various spectroscopic and elemental analyses. The solid-state structures of compounds 5, 8, 9, 10, 14, 15, 16, 17, 19, and 22 were confirmed by single-crystal X-ray analyses. The reaction mechanism of the formation of 19 is also proposed.

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.

Several new 13-vertex closo-metallacarboranes of rare earths incorporating nido-and arachno-carborane ligands have been prepared and structurally characterized. They represent a new class of metallacarboranes bearing a h7-carboranyl ligand recently discovered in our laboratory. This work indicates that the substituents on carborane cage carbons may affect the overall molecular structures of the resultant 13-vertex closo-metallacarborane complexes, but have little influence on the interactions between the central metal ion and nido- or arachno-carborane ligand.

Two new indene compounds, C9H7CH2SiMe2NC4H8 (1) and C9H6-1-Me-3-CH2SiMe2NC4H8 (2), were synthesized by the reaction of C9H6RLi (R) H, Me) with ClCH2SiMe2Cl, followed by treatment with lithium pyrrolidinide C4H8NLi. The interaction of [(Me3Si)2N]3Eu(μ-Cl)-Li(THF)3 with 2 equiv of 1 in refluxing toluene produced, after workup, a novel triple-decker sandwich tetranuclear europium(Ⅱ) compound, [{η:5η:5η1-(C9H5CH2SiMe2NC4H8)2}Eu2(μ-Cl)]2-[μ-η3:η5:η1:η3:η5:η1-(C9H5CH2SiMe2NC4H8)2]âC7H8â(C6H6)0.5 (3), with a coupled indenyl ligand through tandem silylamine elimination, reduction of Eu3+ to Eu2+, and the C-C coupling reactions. To probe the formation pathway of complex 3, the interaction of C9H6-1-Me-3-CH2SiMe2NC4H8 (3) with [(Me3Si)2N]3Eu(μ-Cl)Li(THF)3 was studied. Treatment of [(Me3-Si)2N]3Eu(μ-Cl)Li(THF)3 with 2 equiv of 2 in refluxing toluene temperature or at 60℃ produced, after workup, a monomeric europium(Ⅱ) complex, (η5:η1-C9H5-1-Me-3-CH2SiMe2-NC4H8)2Eu (4), via tandem silylamine elimination/homolysis of the Eu-N bond reactions. The formation pathway for complex 3 was proposed. All the compounds were fully characterized by spectroscopic methods and elemental analyses, and the structures of complexes 3 and 4 were additionally determined by single-crystal X-ray diffraction analyses. It was found that complexes 3 and 4 can function as single-component MMA polymerization initiators, which represent the first examples of europium(Ⅱ) complexes as single-component MMA polymerization catalysts. The solvents and temperature effects' on the activities of the catalysts were also discussed.

A new amine-functionalized carboranyl-indenyl hybrid ligand shows unique properties in stabilizing various kinds of lanthanocene chloride complexes via increasing steric effects imposed by the coordination of NMe2 to the central metal ion, leading to the isolation of kinetic products and monomeric neutral species. Treatment of Me2SiCl(C9H6CH2CH2NMe2) with 1 equiv of Li2C2B10H10 afforded the monolithium salt [Me2Si(C9H5CH2CH2NMe2)-(C2B10H11)]Li(OEt2) (2). Interaction of 2 with 1 equiv of n-BuLi produced the dilithium salt [Me2Si(C9H5CH2CH2NMe2)(C2B10H10)]Li2(OEt2)2 (3). Treatment of 3 with 1 equiv of YbCl3 gave [{η5:η1:σ-Me2Si(C9H5CH2CH2NMe2)(C2B10H10)}YbCl2][Li(THF)4] (4). Upon heating, 4 was converted to [{η5:η1:σ-Me2Si(C9H5CH2CH2NMe2)(C2B10H10)}Yb(μ-Cl)1.5]2[Li(THF)4] (6) and finally to [{η5:η1:σ-Me2Si(C9H5CH2CH2NMe2)(C2B10H10)}Yb(í-Cl)]2 (7) via the elimination of LiCl. Treatment of 6 or its Sm analogue 5 with 2 equiv of sodium amide gave [η5:η1:ó-Me2-Si(C9H5CH2CH2NMe2)(C2B10H10)]Yb(NHC6H3-2,6-Pri 2) (9) or [η5:η1:σ-Me2Si(C9H5CH2CH2-NMe2)(C2B10H10)]Sm(μ-NHC6H3-2,6-Pri 2)(μ-Cl)Li(THF) (8). An equimolar reaction of SmI2 with 3 generated, after addition of LiCl, [{η5:η1:η6-Me2Si(C9H5CH2CH2NMe2)(C2B10H10)Sm}2-(μ-Cl)][Li(THF)4] (10). In sharp contrast, a less reactive YbI2 reacted with 3 in THF, producing only the salt metathesis product [η5:η1:σ-Me2Si(C9H5CH2CH2NMe2)(C2B10H10)]Yb(DME) (11). 11 reacted with 1 equiv of 3 to give the ionic complex {[(μ-η5:η2):η1:σ-Me2Si(C9H5CH2CH2-NMe2)(C2B10H10)]2Yb}{Li(THF)2}2 (12). All complexes were characterized by spectroscopic techniques and elemental analyses. Their structures were all further confirmed by singlecrystal X-ray analyses.