title: Subtle Interactions and Electron Transfer between U(III) , Np(III) , or Pu(III) and Uranyl Mediated by the Oxo Group.
abstract: A dramatic difference in the ability of the reducing An(III) center in AnCp3 (An=U, Np, Pu; Cp=C5 H5 ) to oxo-bind and reduce the uranyl(VI) dication in the complex [(UO2 )(THF)(H2 L)] (L="Pacman" Schiff-base polypyrrolic macrocycle), is found and explained. These are the first selective functionalizations of the uranyl oxo by another actinide cation. At-first contradictory electronic structural data are explained by combining theory and experiment. Complete one-electron transfer from Cp3 U forms the U(IV) -uranyl(V) compound that behaves as a U(V) -localized single molecule magnet below 4 K. The extent of reduction by the Cp3 Np group upon oxo-coordination is much less, with a Np(III) -uranyl(VI) dative bond assigned. Solution NMR and NIR spectroscopy suggest Np(IV) U(V) but single-crystal X-ray diffraction and SQUID magnetometry suggest a Np(III) -U(VI) assignment. DFT-calculated Hirshfeld charge and spin density analyses suggest half an electron has transferred, and these explain the strongly shifted NMR spectra by spin density contributions at the hydrogen nuclei. The Pu(III) -U(VI) interaction is too weak to be observed in THF solvent, in agreement with calculated predictions.
authors.affiliation: EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK. Polly.Arnold@ed.ac.uk.
authors.forename: Polly L
authors.identifier: 0000-0001-6410-5838
authors.initials: PL
authors.lastname: Arnold
authors.affiliation: EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK.|European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Postfach 2340, 76125, Karlsruhe, Germany.
authors.forename: Michał S
authors.initials: MS
authors.lastname: Dutkiewicz
authors.affiliation: EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK.
authors.forename: Markus
authors.initials: M
authors.lastname: Zegke
authors.affiliation: European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Postfach 2340, 76125, Karlsruhe, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Walter
authors.affiliation: European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Postfach 2340, 76125, Karlsruhe, Germany.
authors.forename: Christos
authors.initials: C
authors.lastname: Apostolidis
authors.affiliation: EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK.
authors.forename: Emmalina
authors.initials: E
authors.lastname: Hollis
authors.affiliation: EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK.
authors.forename: Anne-Fréderique
authors.initials: AF
authors.lastname: Pécharman
authors.affiliation: European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Postfach 2340, 76125, Karlsruhe, Germany.
authors.forename: Nicola
authors.initials: N
authors.lastname: Magnani
authors.affiliation: European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Postfach 2340, 76125, Karlsruhe, Germany.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Griveau
authors.affiliation: European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Postfach 2340, 76125, Karlsruhe, Germany.
authors.forename: Eric
authors.initials: E
authors.lastname: Colineau
authors.affiliation: European Commission, Directorate for Nuclear Safety and Security, Joint Research Centre, Postfach 2340, 76125, Karlsruhe, Germany. Roberto.Caciuffo@ec.europa.eu.
authors.forename: Roberto
authors.initials: R
authors.lastname: Caciuffo
authors.affiliation: Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada. Georg.Schreckenbach@umanitoba.ca.
authors.forename: Georg
authors.initials: G
authors.lastname: Schreckenbach
authors.affiliation: EaStCHEM School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FJ, UK. Jason.Love@ed.ac.uk.
authors.forename: Jason B
authors.initials: JB
authors.lastname: Love
keywords: macrocycles; neptunium; plutonium; redox reactions; uranyl cations