Synthesis, structure and solution behaviour of U(III) poly(3,5-diisopropylpyrazoly)borate complexes

The novel KBpiPr2 and the previously described KTpiPr2 react with [UI3(THF)4], in THF, yielding the new compounds [U{κ3-BpiPr2)}3] (1) and [UI2(κ3-TpiPr2)(THF)x] (x=2–3) (2), respectively. Compound 1 is remarkably stable, while 2 decomposes in solution, being the main decomposition product [UI2(κ3-TpiPr2)(κ1-pziPr2H)] (3). The formation of 3 is prevented when [UI3(THF)4] reacts with KTpiPr2 in toluene, in the presence of strong neutral coordinating ligands.