title: [U(III) {N(SiMe2 tBu)2 }3 ]: a structurally authenticated trigonal planar actinide complex.
abstract: We report the synthesis and characterization of the uranium(III) triamide complex [U(III) (N**)3 ] [1, N**=N(SiMe2 tBu)2 (-) ]. Surprisingly, complex 1 exhibits a trigonal planar geometry in the solid state, which is unprecedented for three-coordinate actinide complexes that have exclusively adopted trigonal pyramidal geometries to date. The characterization data for [U(III) (N**)3 ] were compared with the prototypical trigonal pyramidal uranium(III) triamide complex [U(III) (N")3 ] (N"=N(SiMe3 )2 (-) ), and taken together with theoretical calculations it was concluded that pyramidalization results in net stabilization for [U(III) (N")3 ], but this can be overcome with very sterically demanding ligands, such as N**. The planarity of 1 leads to favorable magnetic dynamics, which may be considered in the future design of U(III) single-molecule magnets.
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL (UK).
authors.forename: Conrad A P
authors.initials: CA
authors.lastname: Goodwin
authors.forename: Floriana
authors.initials: F
authors.lastname: Tuna
authors.forename: Eric J L
authors.initials: EJ
authors.lastname: McInnes
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Liddle
authors.forename: Jonathan
authors.initials: J
authors.lastname: McMaster
authors.forename: Inigo J
authors.initials: IJ
authors.lastname: Vitorica-Yrezabal
authors.forename: David P
authors.initials: DP
authors.lastname: Mills
keywords: actinides; ligand design; ligand effects; single-molecule magnets; uranium