Control of Oxo-group functionalization and reduction of the uranyl ion

Polly L. Arnold, Anne-Frédérique Pécharman, Rianne M. Lord, Guy M. Jones, Emmalina Hollis, Gary S. Nichol, Laurent Maron, Jian Fang, Thomas Davin, Jason B. Love

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)

Abstract

Uranyl complexes of a large, compartmental N8-macrocycle adopt a rigid, “Pacman” geometry that stabilizes the UV oxidation state and promotes chemistry at a single uranyl oxo-group. We present here new and straightforward routes to singly reduced and oxo-silylated uranyl Pacman complexes and propose mechanisms that account for the product formation, and the byproduct distributions that are formed using alternative reagents. Uranyl(VI) Pacman complexes in which one oxo-group is functionalized by a single metal cation are activated toward single-electron reduction. As such, the addition of a second equivalent of a Lewis acidic metal complex such as MgN″2 (N″ = N(SiMe3)2) forms a uranyl(V) complex in which both oxo-groups are Mg functionalized as a result of Mg–N bond homolysis. In contrast, reactions with the less Lewis acidic complex [Zn(N″)Cl] favor the formation of weaker U–O–Zn dative interactions, leading to reductive silylation of the uranyl oxo-group in preference to metalation. Spectroscopic, crystallographic, and computational analysis of these reactions and of oxo-metalated products isolated by other routes have allowed us to propose mechanisms that account for pathways to metalation or silylation of the exo-oxo-group.
Original languageEnglish
Pages (from-to)3702-3710
Number of pages9
JournalInorganic Chemistry
Volume54
Issue number7
Early online date23 Mar 2015
DOIs
Publication statusPublished - 6 Apr 2015

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