Ligand‐Supported Facile Conversion of Uranyl(VI) into Uranium(IV) in Organic and Aqueous Media
Radmila Faizova, Farzaneh Fadaei‐Tirani, Rizlan Bernier‐Latmani, Marinella Mazzanti
Abstract
Abstract Reduction of uranyl(VI) to U V and to U IV is important in uranium environmental migration and remediation processes. The anaerobic reduction of a uranyl U VI complex supported by a picolinate ligand in both organic and aqueous media is presented. The [U VI O 2 (dpaea)] complex is readily converted into the cis ‐boroxide U IV species via diborane‐mediated reductive functionalization in organic media. Remarkably, in aqueous media the uranyl(VI) complex is rapidly converted, by Na 2 S 2 O 4 , a reductant relevant for chemical remediation processes, into the stable uranyl(V) analogue, which is then slowly reduced to yield a water‐insoluble trinuclear U IV oxo‐hydroxo cluster. This report provides the first example of direct conversion of a uranyl(VI) compound into a well‐defined molecular U IV species in aqueous conditions.