Synthesis of Cationic Cyclooctatetraene Uranium Complexes by Protonolysis of Borohydride Precursors: The First Cationic Organometallic Borohydride and the First Organometallic Dication of an f Element

Reaction of (COT)U(BH4)(2)(THF) (COT = eta- C8H8, THF = tetrahydrofuran) with NEt3HBPh4 afforded [(COT)U(BH4)(THF)(2)][BPh4] (1), which further reacted with the ammonium salt in, the presence of HMPA to give [(COT) U(HMPA)(3)][BPh4](2) (2); the crystal structure of a pyridine solvate of 2 has been determined.