{"id":884,"date":"2017-12-01T11:08:36","date_gmt":"2017-12-01T11:08:36","guid":{"rendered":"http:\/\/www.mub.eps.manchester.ac.uk\/in-abstract\/?p=884"},"modified":"2018-04-17T15:35:05","modified_gmt":"2018-04-17T14:35:05","slug":"evidence-for-addition-and-reductive-elimination-at-uranium","status":"publish","type":"post","link":"https:\/\/www.mub.eps.manchester.ac.uk\/in-abstract\/evidence-for-addition-and-reductive-elimination-at-uranium\/","title":{"rendered":"Evidence for single metal two electron oxidative addition and reductive elimination at uranium"},"content":{"rendered":"

An actinide element mimicking the chemistry of transition metals<\/strong><\/p>\n

Single-metal, two-electron oxidative addition and reductive elimination are fundamental reactions for transition metals that underpin most homogeneous catalytic cycles. These reactions are typically regarded as the preserve of the d-block, where metals typically have facile and reversible redox chemistry that makes them suitable for catalysis. In contrast, however, the f-block elements typically engage only in one-electron transfer reactions and such reactions are usually irreversible and thus stoichiometric in nature.<\/p>\n

Utilising low-valent uranium(III) complexes, with sterically very open coordination spheres, researchers at the University of Manchester and their colleagues in Nottingham and Toulouse have now discovered that diazobenzene can react to give uranium(V) products, where a formal oxidative addition has occurred. They also found evidence for a thermally instigated reductive elimination. Computer modelling revealed a reaction intermediate where a uranium f-orbital \u03b4-back-bonds into the \u03c0*-orbital of azobenzene. This binding mode would not normally be expected, and may contribute to the observed reactivity.<\/p>\n

Although the system is not well balanced, it establishes evidence for reversible oxidative addition and reductive elimination at uranium, thus raising the tantalising possibility that with a better balanced system d-block reactivity could be performed by an f-element. However, the presence of f-orbitals at uranium would probably mean that any such reactivity would be different from traditional d-block catalysis, and so new types of catalysis might result.<\/p>\n

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