| Abstract
| - The compound Me2C(C5H5)(C2B10H11) (I) could be conveniently converted into the monoanion [Me2C(C5H4)(C2B10H11)]- (I-1) and the dianion [Me2C(C5H4)(C2B10H10)]2- (I-2) by treatmentwith excess NaH and 2 equiv of n-BuLi, respectively. The monoanion I-1 could be furtherconverted into the trianion [Me2C(C5H4)(nido-C2B10H11)]3- (I-3) by reaction with 2 equiv ofNa metal in THF and into the pentaanion [Me2C(C5H4)(arachno-C2B10H11)]5- in the presenceof LnCl3 and excess Na metal in THF. Reactions of LnCl3 with the monoanion I-1 in molarratios of 1:1, 1:2, and 1:3 generated the mono-, bis-, and tris-ligated organolanthanidecompounds [η5-Me2C(C5H4)(C2B10H11)]LnCl2(S)n ((S)n = (THF)3, Ln = Er (1), Sm (2); (S)n =(DME)2, Ln = Nd (3)), [η5-Me2C(C5H4)(C2B10H11)]2SmCl(THF)2 (4), and [η5-Me2C(C5H4)(C2B10H11)]3Sm·0.5C7H8 (5), respectively. Reaction of LnCl3 with 1 or 2 equiv of the dianionI-2 gave the same compound, [{η5:σ-Me2C(C5H4)(C2B10H10)}2Ln][Li(DME)3] (Ln = Sm (6),Yb (7)). 6 could also be prepared by treatment of 2 with 1 equiv of the dianion I-2. Reactionof YbI2 with 1 equiv of I-2, followed by treatment with 1 equiv of I-1, also gave compound7. However, YbI2 reacted with 2 equiv of I-1 to afford the organoytterbium(II) compound[η5-Me2C(C5H4)(C2B10H11)]2Yb(THF)2 (8). Interaction of SmI2 with 2 equiv of I-1 yielded twocompounds, the redox product [η5:η6-Me2C(C5H4)(C2B10H11)]Sm(THF)2 (9) and the tris-ligatedcompound 5. The compound [η5:η6-Me2C(C5H4)(C2B10H11)]Er(THF)2 (10), an analogue of 9,was prepared by treatment of 1 with 2 equiv of Na metal or by reaction of ErCl3 with 1equiv of I-3. Treatment of 10 with excess Na metal gave the first organolanthanide compoundcontaining a η7-carboranyl ligand, [{[η5:η7-Me2C(C5H4)(C2B10H11)]Er}2{Na4(THF)9}]n (11). ItsDy analogue, [{[η5:η7-Me2C(C5H4)(C2B10H11)]Dy}2{Na4(THF)9}]n (12), could also be preparedby a “one-pot” reaction of DyCl3, I-1, and excess Na metal. Treatment of 11 with 2 equiv ofErCl3 in THF gave the novel tetranuclear cluster [{η5:η7-Me2C(C5H4)(C2B10H11)}Er2(μ-Cl)(THF)3]2 (13), in which the Er3+ ions replace all Na+ ions in 11. All of these compounds werefully characterized by various spectroscopic data and elemental analyses. The solid-statestructures of compounds 4−11 and 13 have been confirmed by single-crystal X-ray analyses.
- A versatile ligand, Me2C(C5H5)(C2B10H11), can be converted into the monoanion, the dianion, the trianion, and even the pentaanion under proper reaction conditions, which has led to the isolation and structural characterization of a variety of organolanthanide compounds.
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