Syntheses of Divalent Lanthanide Tetradecahydrodecaborates and Decahydrodecaborates. The X-ray Crystal Structure of (CH3CN)6Yb(Mu-H)2B10H12.2CH3CN.

摘要

The chemistry and bonding of boron hydrides to the lanthanide elements remains largely unexplored. While numerous lanthanide organometallic complexes are known, the only boron hydride compounds reported are the trivalent closo-B12H12(2-) salts and borohydride, BH4(-) derivatives. No detailed structural data are available: however, the gadolinium complex (BH4)3Gd(THF)3 has been reported to be isomorphous with the pseudo-lanthanide derivative (BH4)3Y(THF)3. Compounds containing the common divalent ions (Ln = Sm, Eu, Yb) and binary boron hydride ligands are unknown: however, carborane complexes have been reported in which the metal occupies the vertex site of an icosahedron as well as a sigma-bonded carborane compound. Herein we report the synthesis and the first example of a structurally characterized polyhedral boron hydride bound to a lanthanide center, (CH3CN)6Yb(mu-H)2B10H12-2CH3CN. We also report the syntheses of the divalent lanthanide decahydrodecaborate compounds EuB10H10 and YbB10H10 (III). Compounds I-III are derived from reactions of decaborane, B10H14, with the lanthanide metals (Ln = Eu, Yb) in liquid ammonia. Both europium and ytterbium dissolve in NH3 to give deep blue, highly reducing solutions containing Ln(2+) and solvated electrons. Decaborane is easily reduced in these solutions, from which several products can be isolated. Reprints. (aw)