A new carbon-bridged versatile ligand Me2C(C9H7)(C2B10H11) (1) has been designed and successfully prepared by treatment of Li2C2B10H10 with 1 equiv of 6,6-dimethylbenzofulvene followed by hydrolysis with a saturated NH4Cl aqueous solution. 1 can be conveniently converted into the monoanion [Me2C(C9H6)(C2B10H11)]Li (2) and the dianion [Me2C(C9H6)(C2B10H10)]Li2 (3) by treatment with 1 or 2 equiv of n-BuLi, respectively. Both NaNH2 and NaH can only convert 1 into the monoanion, but cannot deprotonate the CH proton of the carborane cage in 1. These results differ significantly from those of a closely related analogue, Me2Si(C9H7)(C2B10H11). Treatment of SmI2 with 1 equiv of 3, followed by reaction with 1 equiv of 2, gave the redox product rac-[Li(DME)2][{η5:σ-Me2C(C9H6)(C2B10H10)}2Sm] (4). 4 can also be prepared by reaction of SmI2 with 1 equiv of 3 in a relatively lower yield. These two reactions may undergo different pathways, an intramolecular electron-transfer pathway for the former and an intermolecular electron-transfer pathway for the latter. The latter reaction can be accelerated by addition of CS2 or PhC⋮CPh, which led to the isolation of rac-[Li(THF)4][{η5:σ-Me2C(C9H6)(C2B10H10)}2Sm] (5). Unlike the SmI2 case, an equimolar reaction between 3 and YbI2 afforded the Yb(II) compound [η5:σ-Me2C(C9H6)(C2B10H10)]Yb(DME)2 (6). 6 can react with 1 equiv of 2 to generate a C−H bond reduction product, rac-[Li(DME)3][{η5:σ-Me2C(C9H6)(C2B10H10)}2Yb]·C6H5CH3 (7). Reaction of LnCl3 with 1 or 2 equiv of 2 yielded organolanthanide dichloride and monochloride compounds, respectively, [η5-Me2C(C9H6)(C2B10H11)]GdCl2(THF)2 (15) and [η5-Me2C(C9H6)(C2B10H11)]2LnCl(THF)(OEt2) (Ln = Y (8), Yb (9)). Treatment of 9 with 1 or 2 equiv of MeLi gave deprotonation products rac-[{η5:σ-Me2C(C9H6)(C2B10H10)}{η5-Me2C(C9H6)(C2B10H11)}]Yb(μ-Cl)Li(DME)2 (10) and rac-[Li(DME)2][{η5:σ-Me2C(C9H6)(C2B10H10)}2Yb] (11), respectively. Reaction of LnCl3 with 2 equiv of 3 also afforded ionic compounds rac-[Li(DME)2][{η5:σ-Me2C(C9H6)(C2B10H10)}2Ln] (Ln = Yb (11), Nd (12), Er (13)). Recrystallization of 7 from a mixed solvent of toluene/DME (10:1) gave meso-[Li(DME)3][{η5:σ-Me2C(C9H6)(C2B10H10)}2Yb]·2C6H5CH3 (14). All of these compounds were fully characterized by various spectroscopic and elemental analyses. The molecular structures of 4−7, 11, 12, and 14 have been confirmed by single-crystal X-ray analyses. The structural analyses reveal that the anions in 7 (or 11) and 14 are one pair of diastereomers.

The compound Me 2 C(C 5 H 5 )(C 2 B 10 H 11 ) (I) could be conveniently converted into the monoanion [Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )] -(I-1) and the dianion [Me 2 C(C 5 H 4 )(C 2 B 10 H 10 )] 2-(I-2) by treatment with excess NaH and 2 equiv of n-BuLi, respectively. The monoanion I-1 could be further converted into the trianion [Me 2 C(C 5 H 4 )(nido-C 2 B 10 H 11 )] 3-(I-3) by reaction with 2 equiv of Na metal in THF and into the pentaanion [Me 2 C(C 5 H 4 )(arachno-C 2 B 10 H 11 )] 5in the presence of LnCl 3 and excess Na metal in THF. Reactions of LnCl 3 with the monoanion I-1 in molar ratios of 1:1, 1:2, and 1:3 generated the mono-, bis-, and tris-ligated organolanthanide compounds 4), and [η 5 -Me 2 C(C 5 H 4 )-(C 2 B 10 H 11 )] 3 Sm‚0.5C 7 H 8 (5), respectively. Reaction of LnCl 3 with 1 or 2 equiv of the dianion I-2 gave the same compound, [{η 5 :σ-Me 2 C(C 5 H 4 )(C 2 B 10 H 10 )} 2 Ln][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. Reaction of YbI 2 with 1 equiv of I-2, followed by treatment with 1 equiv of I-1, also gave compound 7. However, YbI 2 reacted with 2 equiv of I-1 to afford the organoytterbium(II) compound [η 5 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )] 2 Yb(THF) 2 (8). Interaction of SmI 2 with 2 equiv of I-1 yielded two compounds, the redox product [η 5 :η 6 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Sm(THF) 2 ( 9) and the tris-ligated compound 5. The compound [η 5 :η 6 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Er(THF) 2 ( 10), an analogue of 9, was prepared by treatment of 1 with 2 equiv of Na metal or by reaction of ErCl 3 with 1 equiv of I-3. Treatment of 10 with excess Na metal gave the first organolanthanide compound containing a η 7 -carboranyl ligand, [{[η 5 :η 7 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Er} 2 {Na 4 (THF) 9 }] n (11). Its Dy analogue, [{[η 5 :η 7 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Dy} 2 {Na 4 (THF) 9 }] n (12), could also be prepared by a "one-pot" reaction of DyCl 3 , I-1, and excess Na metal. Treatment of 11 with 2 equiv of ErCl 3 in THF gave the novel tetranuclear cluster [{η 5 :η 7 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )}Er 2 (µ-Cl)-(THF) 3 ] 2 (13), in which the Er 3+ ions replace all Na + ions in 11. All of these compounds were fully characterized by various spectroscopic data and elemental analyses. The solid-state structures of compounds 4-11 and 13 have been confirmed by single-crystal X-ray analyses.

Treatment of Me2Si(C9H7)(C2B10H11) with 4 equiv of NaNH2 in THF, followed by reaction with 1 equiv of LnCl3 at room temperature, afforded [{(η 5-μ 2-C9H6SiMe2NH)Ln}2(μ 3-Cl)(THF)]2(μ 4-NH)·nOC4H8 (n = 1, Ln = Gd (Ia), Er (Ib); n = 0, Ln = Dy (Ic)), which represent not only the first examples of organometallic clusters containing a central μ 4-imido group but also the first organolanthanide indenyl clusters to be reported. Another type of tetranuclear cluster, [{(η 5-C9H6SiMe2)2N}(μ 2-NH2)Ln2(THF)2]2(μ 3-Cl)2(μ 2-Cl)2·THF (Ln = Gd (IIa), Y (IIb)), was obtained if the above reactions were carried out at reflux temperature. This type of cluster can also be prepared by refluxing cluster type I in THF in the presence of NaCl. Treatment of Me2Si(C9H7)(C2B10H11) with 8 equiv of NaNH2 in THF, followed by reaction with 1 equiv of LnCl3 at room temperature, gave the trinuclear clusters [(η 5-C9H6SiMe2)2N][μ 2,μ 2-Me2Si(NH)2](η 5-μ 2-C9H6SiMe2NH)(μ 2-Cl)2Ln3(THF)3 (Ln = Gd (IIIa), Er (IIIb)). These results indicate that NaNH2 serves as both base and nucleophile in the reactions. The o-carborane can be recovered by sublimation under vacuum. The structures of all tetra- and trinuclear clusters were confirmed by single-crystal X-ray analyses.

Up to eight redox-active ferrocenyl units have been incorporated, through the unsaturated ethynyl linkers, on the periphery of a series of cyclic tetrapyrrole derivatives including zinc(II) phthalocyanine and 2,3-naphthalocyanine, and nickel(II) meso-diphenylporphyrin. The synthesis of the former two macrocycles 4 and 7 involves the Sonogashira coupling reaction of ferrocenylethyne with 4,5-dichlorophthalonitrile (1) or 6,7-dibromonaphthalonitrile (5), respectively, followed by a base-promoted cyclization. The meso-bis(ferrocenylethynyl)porphyrin 11 has been prepared from the dibromo analogue 10 also by a palladium-catalyzed coupling reaction. These novel macrocyclic compounds have been spectroscopically and electrochemically characterized. As revealed by cyclic voltammetry, the ferrocenyl moieties appear to be electrochemically independent in these complexes and there is no significant electronic coupling among the iron(II) centers.

Reaction of Me 2 Si(C 5 Me 4 H)Cl with 1 equiv of Li 2 C 2 B 10 H 10 in toluene/Et 2 O gave the monoanionic salt [Me 2 Si(C 5 Me 4 )(C 2 B 10 H 11 )]Li(OEt 2 ) 0.5 (1), which could be conveniently converted into the dianionic salt [{[(µ-η 5 ):σ-Me 2 Si(C 5 Me 4 )(C 2 B 10 H 10 )]Li(THF)} 2 Li][Li(THF) 4 ]‚ THF (2) by treatment with 1 equiv of n-BuLi. 1 reacted with 1 equiv of LnCl 3 in THF to give [η 5 -Me 2 Si(C 5 Me 4 )(C 2 B 10 H 11 )]LnCl 3 Li(THF) 3 (Ln ) Nd (3), Sm (4)). 3 could further react with 1 equiv of 1 to afford [η 5 -Me 2 Si(C 5 Me 4 )(C 2 B 10 H 11 )] 2 Nd(µ-Cl) 2 Li(OEt 2 )(THF) ( 6), which could also be prepared from the reaction of NdCl 3 with 2 equiv of 1. Partial hydrolysis of 4 resulted in the isolation of the novel cluster [{[η 5 -Me 2 Si(C 5 Me 4 )(C 2 B 10 H 11 )]Sm} 2 (µ 2 -Cl) 3 (µ 3 -Cl) 4 Li(OEt 2 ) 2 -Li(THF) 2 Sm(µ 4 -O)] 2 (5). Treatment of 1 with 4 equiv of NaNH 2 in THF, followed by reaction with 1 equiv of YbCl 3 , produced (η 5 -C 5 Me 4 H) 2 Yb(µ-Cl) 2 Li(THF) 2 ( 7). An equimolar reaction between 2 and NdCl 3 yielded the anionic compound [{η 5 : σ-Me 2 Si(C 5 Me 4 )(C 2 B 10 H 10 )} 2 Nd]-[Li(DME) 3 ] (11). Interaction of LnCl 3 with 0.5 equiv of 2 resulted in the isolation of the lanthanocene chloride compounds [{η 10)). Reaction of 9 with 2 equiv of NaN(SiMe 3 ) 2 gave the unsolvated compound [η 5 : σ-Me 2 Si(C 5 Me 4 )(C 2 B 10 H 10 )]YN(SiMe 3 ) 2 (12). Treatment of LnI 2 with 0.5 equiv of 2 afforded the ionic organolanthanide(II) compounds [{η 5 : σ-Me 2 Si(C 5 Me 4 )(C 2 B 10 H 10 )}LnI 2 ][Li(DME) 3 ] 2 (Ln ) Sm (13), Yb ( 14)). All of these new compounds were characterized by various spectroscopic data and element analyses. The solidstate structures of compounds 2, 5-7, 10, and 14 were further confirmed by single-crystal X-ray analyses.