Organometallic Compounds of the Lanthanides. 127 [1] Synthesis of Monomeric Bis(cyclopentadienyl)lanthanide Tetrahydroborates with Bulky Cyclopentadienyl Ligands. Single Crystal X-ray Structures of [(η5-C5Me5)2SmBH4(THF)] and [(η5-C5Me4Et)2Y(μ-H)2BH2(THF)]

The trichlorides of yttrium, samarium, and lutetium react with 2 equivalents of Na[C5H4 tBu] and 1 equivalent of NaBH4 to give [(η5-C5H4 tBu)2LnBH4(THF)] (Ln = Y (1), Sm (2), Lu (3)) or with 2 equivalents of Na[C5Me4R] and 1 equivalent of NaBH4 to form [(η5-C5Me4R)2 · LnBH4(THF)] (R = H, Ln = Y (4), Sm (5), Lu (6); R = Me, Ln = Y (7), Sm (8), Lu (9); R = Et, Ln = Y (10), Sm (11), Lu (12); R = iPr, Ln = Y (13), Sm (14), Lu (15)). The new compounds have been characterized by elemental analysis, NMR spectroscopy and mass spectrometry. The crystal structures of 8 and 10 were determined by single crystal X-ray diffraction.