The first neodymacarborane cluster: A structural investigation

The title compound, {eta(5)-1-Nd-2,3-(SiMe3)(2)-2,3-C2B4H4](3)[(mu 2)-1-Li- 2,3-(SiMe3)(2)-2,3-C2B4H4)(3) ((mu 3)-OBut)[(mu 2)-Li-(C4H8O)](3)((mu 3)-O) }, was crystallized in a monoclinic space group P2(1)/m in which the minor plane of symmetry passes through three metals (Nd2, Li1, Li3) and two oxyge n atoms (O1, O2). The plane also bisects two carborane cages (C21 through B 23A, C31 through B33A) and one THF (O71 through C73A). The structure of thi s cluster consists of three closo-neodymacarboranes, three cage-bridged Li( THF) units, and three Nd-bridged closo-lithiacarboranes that form a tricapp ed trigonal prism with Nd atoms in the capping positions. A benzene molecul e is also in the unit cell as a result of a recrystallization of the compou nd in benzene solvent. A centrally located O atom triply-brigdes the Nd ato ms [Nd-O = 2.246 (4), 2.244 (8), and 2.246 (4) Angstrom], forming a nearly coplanar arrangement [Nd-O-Nd = 119.7 (3), 119.2 (2), and 119.7 (3) degrees ]. The t-butoxy group in the cluster is linked to the apical lithium atoms of the three closo-lithiacarboranes in a distorted tetrahedral fashion [ave rage Li-O-Li = 107.7 degrees and average C-O-Li = 111.2 degrees].