Monocyclooctatetraene uranium amide compounds in the +4 and +5 oxidation states

Abstract

The compounds M[U(cot)(NEt₂)₃]1(cot =η-C₈H₈, M = Li or K) were prepared by (a) reaction of [U(NEt₂)₄] or [U(NEt₂)₃][BPh₄] with K₂(cot), (b) treatment of UCl₄ with LiNEt₂ and K₂(cot) and (c) reaction of [U(cot)₂] with LiNEt₂. The compound [U(cot)(NEt₂)₂(thf)]2(thf = tetrahydrofuran) was synthesized by treating [U(NEt₂)₂Cl₂] with K₂(cot). Uranium(V) compounds were obtained by oxidation of 1 and 2. Treatment of 1 with TlBPh₄ afforded [U(cot)(NEt₂)₃] which was tranformed into [U(cot)(OPrⁱ)₃] by alcoholysis. Complex 2 reacted with AgBPh₄ or Tl(cp)(cp =η-C₅H₅) to give [U(cot)(NEt₂)₂(thf)][BPh₄] and [U(cot)(cp)(NEt₂)₂] respectively, the crystal structure of the first of which has been determined.