Cyclopentadienyl vs indenyl substituents.: Organolanthanide complexes and biscarborane compounds derived from a versatile ligand, Me2Si(C9H7) (C2B10H11)

A versatile compound, Me2Si(C9H7)(C2B10H11) can be conveniently converted into the monoanion [Me2Si(C9H6)(C2B10H11)]Na, the dianion [Me2Si(C9H6)(C2B10H10)]Na-2, and the trianion [Me2Si(C9H6)(C2B10H11)]K-3 by treatment with 1 equiv or excess amounts of NaH or K metal in THF, respectively. Reaction of LnCl(3) with 1 equiv of [Me2Si(C9H6)(C2B10H11)]Na in THF gave dichloride complexes [eta(5)-Me2Si(C9H6)(C2B10H11)]LnCl(2)(THF)(3) (Ln = Nd (1), Er (2)). They can further react with another equivalent of [Me2Si(C9H6)(C2B10H11)]Na to afford monochloride complexes [eta(5)-Me2Si(C9H6)(C2B10H11)](2)LnCl(THF)(2) (Ln = Ce (3), Nd (4), Sm (5), Er (6)), which can also be prepared by treatment of LnCl(3) with 2 equiv of [Me2Si(C9H6)(C2B10H11)]Na in THF. 4 reacts with excess NaH in THF to produce [Na(THF)(6)][{eta(5):sigma-Me2Si(C9H6)(C2B10H10)}(2)Nd] (7), which can also be prepared from the reaction of NdCl3 with 2 equiv of [Me2Si(C9H6)(C2B10H11)]Na in THF. Treatment of 2 with 2 equiv of K metal at room temperature yielded [eta(5):eta(6)-Me2Si(C9H6)(C2B10H11)]Er(THF)(2) (8) Reaction of 6 with 1 equiv of NaH afforded [{eta(5):sigma-Me2Si(C9H6)(C2B10H10)}{eta(5)-Me2Si(C9H6)(C2B10H11)}]Er(mu-Cl)Na(THF)(3) (9), which can also be prepared from the reaction of 2 with 1 equiv of [Me2Si(C9H6)(C2B10H10)]Na-2 in THF. Treatment of 9 with a mixture of 1 equiv of NaOH and excess NaH in THF generated the dinuclear complex [Na-2(THF)(11)][{eta(5):sigma-Me2Si(C9H6)(C2B10H10)}-{mu-eta(5):sigma-(C9H6)SiMe2O}Er](2) (10). Treatment of Me2Si(C9H7)(C2B10H11) with excess NaH in THF under UV-light followed by reaction with 1 equiv of LnCl(3) resulted in the isolation of unprecedented biscarborane compounds [LnCl(2)(THF)(5)][mu-CH-(closo-C2B10H11)-nido-CB10H11] (Ln = Er (11), Y (12)). All of these complexes were characterized by various spectroscopic and elemental analyses. The solid-state structures of 7 and 9-12 were confirmed by single-crystal X-ray analyses.