Isolation of U(ii) compounds using strong donor ligands, C5Me4H and N(SiMe3)2, including a three-coordinate U(ii) complex

Abstract

New examples of uranium in the formal +2 oxidation state have been isolated by reduction of Cp^tet₃U (Cp^tet = C₅Me₄H) and U(NR₂)₃ (R = SiMe₃) in the presence of 2.2.2-cryptand (crypt) to produce [K(crypt)][Cp^tet₃U] and [K(crypt)][U(NR₂)₃], respectively. Both complexes have properties consistent with 5f³6d¹ electron configurations and demonstrate that the U(II) ion can be isolated with electron donating ligands.