A permethylcyclopentadienyl carbollide scandium complex, Sc_2Si_4O_3C_(50)B_(18)Li_2H_(114)

Abstract

Tris(tetrahydrofuran)lithium lithium bis[3-bis (trimethylsilyl)methyl-3-(η^5-pentamethylcyclopentadienyl)-1,2-dicarba-3-scanda-closo-dodecaborate- (l-)], [Li(C_4H_80)_3].Li[Sc(C_2B_9H_(11))(C_(10)H_(15))CH {Si( CH_3)_3)]_2]_2, M_r = 1174.16, triclinic, Pl, ɑ = 8.924 (4), b = 18.467 (5), c = 22.165 (3)Å, ɑ = 91.42 (2), β = 92.36 (2), y = 92.21 (3)º, v = 3645.6 (18) A^3, Z = 2, D_x = 1.07 g cm^(-3), λ(Mo Kɑ)= 0.71073 Å, μ = 2.84 cm^(-1), F(000) = 1264, room temperature, 294 K, R = 0.064 for 3069 reflections. Each Sc atom is bonded to one Cp^* in an 175 fashion, to one carbollide ligand in an η^5 fashion (completing a distorted icosahedron), and to one -CH(SiMe_3)_2 group in the cleft; the angle at Sc subtended by the centers of the two η^5 groups is 137.8°. Two of these complexes share an Li atom which is loosely bonded to three B atoms of each carbollide, creating a dimeric monoanion. The counterion, a second Li atom, is coordinated to three tetrahydrofuran molecules.