title: Molecular and electronic structure of terminal and alkali metal-capped uranium(V) nitride complexes.
abstract: Determining the electronic structure of actinide complexes is intrinsically challenging because inter-electronic repulsion, crystal field, and spin-orbit coupling effects can be of similar magnitude. Moreover, such efforts have been hampered by the lack of structurally analogous families of complexes to study. Here we report an improved method to U≡N triple bonds, and assemble a family of uranium(V) nitrides. Along with an isoelectronic oxo, we quantify the electronic structure of this 5f1family by magnetometry, optical and electron paramagnetic resonance (EPR) spectroscopies and modelling. Thus, we define the relative importance of the spin-orbit and crystal field interactions, and explain the experimentally observed different ground states. We find optical absorption linewidths give a potential tool to identify spin-orbit coupled states, and show measurement of UV···UVsuper-exchange coupling in dimers by EPR. We show that observed slow magnetic relaxation occurs via two-phonon processes, with no obvious correlation to the crystal field.
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: David M
authors.initials: DM
authors.lastname: King
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cleaves
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Ashley J
authors.initials: AJ
authors.lastname: Wooles
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Benedict M
authors.initials: BM
authors.lastname: Gardner
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Nicholas F
authors.initials: NF
authors.lastname: Chilton
authors.affiliation: School of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Floriana
authors.initials: F
authors.lastname: Tuna
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
authors.forename: William
authors.initials: W
authors.lastname: Lewis
authors.affiliation: School of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Eric J L
authors.initials: EJL
authors.lastname: McInnes
authors.affiliation: School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Liddle