Two‐Electron Reductive Carbonylation of Terminal Uranium(V) and Uranium(VI) Nitrides to Cyanate by Carbon Monoxide1. Issue 39 (30th July 2014)

• Record Type: Journal Article
• Authors: Cleaves, Peter A.; King, David M.; Kefalidis, Christos E.; Maron, Laurent; Tuna, Floriana; McInnes, Eric J. L.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T.
• Is Part Of: Angewandte Chemie international edition. Volume 53:Issue 39(2014)
• Page Start: 10412
• Page End: 10415
• Publication Date: 2014-07-30
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201406203
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Two‐electron reductive carbonylation of the uranium(VI) nitride [U(Tren^TIPS)(N)] (<bold>2</bold>, Tren^TIPS=N(CH₂CH₂NSi<italic>i</italic>Pr₃)₃) with CO gave the uranium(IV) cyanate [U(Tren^TIPS)(NCO)] (<bold>3</bold>). KC₈ reduction of <bold>3</bold> resulted in cyanate dissociation to give [U(Tren^TIPS)] (<bold>4</bold>) and KNCO, or cyanate retention in [U(Tren^TIPS)(NCO)][K(B15C5)₂] (<bold>5</bold>, B15C5=benzo‐15‐crown‐5 ether) with B15C5. Complexes <bold>5</bold> and <bold>4</bold> and KNCO were also prepared from CO and the uranium(V) nitride [{U(Tren^TIPS)(N)K}₂] (<bold>6</bold>), with or without B15C5, respectively. Complex <bold>5</bold> can be prepared directly from CO and [U(Tren^TIPS)(N)][K(B15C5)₂] (<bold>7</bold>). Notably, <bold>7</bold> reacts with CO much faster than <bold>2</bold>. This unprecedented f‐block reactivity was modeled theoretically, revealing nucleophilic attack of the π* orbital of CO by the nitride with activation energy barriers of 24.7 and 11.3 kcal mol⁻¹ for uranium(VI) and uranium(V), respectively. A remarkably simple two‐step, two‐electron cycle for the conversion of azide to nitride to cyanate using <bold>4</bold>, NaN₃ and CO is presented.</p> </abstract>