Lanthanide Borohydrides as Precursors to Organometallic Compounds. Mono(cyclooctatetraenyl) Neodymium Complexes

Reactions of Nd(BH4)3(THF)3 (1) with KCp* (Cp* = η-C5Me5), KC4Me4P, and K2C8H8 gave the organometallic derivatives (Cp*)Nd(BH4)2(THF)2 (2), [K(THF)][(C4Me4P)2Nd(BH4)2] (3), and (COT)Nd(BH4)(THF)2 (4) (COT = η-C8H8), respectively. Treatment of 4 with NEt3HBPh4 afforded the cationic complex [(COT)Nd(THF)4][BPh4] (5). The mixed ring compound (COT)Nd(Cp*)(THF) (6), the alkoxide [(COT)Nd(OEt)(THF)]2 (7), and the thiolates Na[(COT)Nd(StBu)2] (8) and [Na(THF)2][{(COT)Nd}2(StBu)3] (9) were synthesized by treating 4 or 5 with the alkali metal salt of the corresponding anionic reagent. The X-ray crystal structures of 7 and of a toluene solvate of 9 have been determined.