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Uranium(III)-carbon multiple bonding supported by arene ?-bonding in mixed-valence hexauranium nanometre-scale rings.

ABSTRACT: Despite the fact that non-aqueous uranium chemistry is over 60 years old, most polarised-covalent uranium-element multiple bonds involve formal uranium oxidation states IV, V, and VI. The paucity of uranium(III) congeners is because, in common with metal-ligand multiple bonding generally, such linkages involve strongly donating, charge-loaded ligands that bind best to electron-poor metals and inherently promote disproportionation of uranium(III). Here, we report the synthesis of hexauranium-methanediide nanometre-scale rings. Combined experimental and computational studies suggest overall the presence of formal uranium(III) and (IV) ions, though electron delocalisation in this Kramers system cannot be definitively ruled out, and the resulting polarised-covalent U?=?C bonds are supported by iodide and ?-bonded arene bridges. The arenes provide reservoirs that accommodate charge, thus avoiding inter-electronic repulsion that would destabilise these low oxidation state metal-ligand multiple bonds. Using arenes as electronic buffers could constitute a general synthetic strategy by which to stabilise otherwise inherently unstable metal-ligand linkages.

SUBMITTER: Wooles AJ

PROVIDER: S-EPMC5974406 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature

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Uranium(III)-carbon multiple bonding supported by arene δ-bonding in mixed-valence hexauranium nanometre-scale rings.

Wooles Ashley J AJ Mills David P DP Tuna Floriana F McInnes Eric J L EJL Law Gareth T W GTW Fuller Adam J AJ Kremer Felipe F Ridgway Mark M Lewis William W Gagliardi Laura L Vlaisavljevich Bess B Liddle Stephen T ST

Nature communications 20180529 1

Despite the fact that non-aqueous uranium chemistry is over 60 years old, most polarised-covalent uranium-element multiple bonds involve formal uranium oxidation states IV, V, and VI. The paucity of uranium(III) congeners is because, in common with metal-ligand multiple bonding generally, such linkages involve strongly donating, charge-loaded ligands that bind best to electron-poor metals and inherently promote disproportionation of uranium(III). Here, we report the synthesis of hexauranium-meth ...[more]

PMID: 29844376

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Uranium(III)-carbon multiple bonding supported by arene ?-bonding in mixed-valence hexauranium nanometre-scale rings.

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Uranium(III)-carbon multiple bonding supported by arene δ-bonding in mixed-valence hexauranium nanometre-scale rings.

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