Polly Louise Arnold

A series of rare earth complexes of the form Ln(LR)3 supported by bidentate ortho-aryloxide-NHC ligands are reported (LR = O(o-C6H2-tBu2-2,6-CN(C2H2)NR); R = iPr, tBu, Mes; Ln = Ce, Sm, Eu). The cerium complexes react cleanly and quantitatively insert carbon dioxide exclusively into all three cerium carbene bonds, forming Ce(LR.CO2)3. The insertion is reversible only for the mesityl-substituted complex Ce(LMes)3.

Neptunium complexes in the formal oxidation states II, III, and IV supported by cyclopentadienyl ligands are explored, and significant differences between Np and U highlighted as a result. A series of neptunium(III) cyclopentadienyl (Cp) complexes [Np(Cp) ], its bis-acetonitrile adduct [Np(Cp) (NCMe) ], plus its KCp adduct K[Np(Cp) ] and [Np(Cp') ] (Cp' = C H SiMe ) have been made and characterised providing the first single crystal x-ray analyses of Np Cp complexes.