Nucleophilic carbene complexes of Uranium(IV) and (VI)
Jean-Claude Berthet, Jean-Christophe Tourneux, Thibault Cantat, Nicolas Mézailles, Pierre Thuéry, Michel Ephritikhine logo_tutelle logo_tutelle 

Formation of organo-compounds involving [Mf]=C double bond and description of the nature of this formally double bond is a subject of considerable interest for some years. The LCCEf, in collaboration with the Ecole Polytechnique, focused on the interaction of the novel dianionic carbene SCS2- with uranium ions.

Conditions were found which permit the use of UCl4 instead of the less convenient borohydride starting material U(BH4)4 to prepare the mono-, bis- and tris- uranium(IV) carbene complexes with the dianionic ligand [C(Ph2PS)2]2 (SCS2) (Fig . 1).

 

The species [Li(THF)2U(SCS)Cl3(THF)], [U(SCS)2(THF)2] and [{Li(OEt2)}2U(SCS)3] proved of interest for developing the carbene chemistry of U(IV), as illustrated with the synthesis of carbene compounds with cyclopentadienyl and cyclooctatetraenyl ancillary ligands.

The weakly reducing anions shown in Fig. 1 were also useful for the synthesis, directly from uranyl UO2X2 precursors, of rare stable organometallic uranyl complexes featuring single and double uranium(VI)−carbon bonds.

Density functional theory analyses of these U(IV) and U(VI)complexes showed that the U−C and U=C bonds are polarized toward the nucleophilic carbon.


  1. Easy access to uranium nucleophilic carbene complexes
    J.-C. Tourneux, J.-C. Berthet, P. Thuéry, N. Mézailles, P. Le Floch, M. Ephritikhine, Dalton Trans., 2010, 39, 2494.
     
  2. Uranium(IV) nucleophilic carbene complexes
    J.-C. Tourneux, J.-C. Berthet, T. Cantat, P. Thuéry, N. Mézailles, P. Le Floch, M. Ephritikhine, Organometallics, 2011, 30, 2957.

  3. Exploring the uranyl organometallic chemistry: from single to double uranium−carbon bonds
    J.-C. Tourneux, J.-C. Berthet, T. Cantat, P. Thuéry, N. Mézailles, M.  Ephritikhine, J. Am. Chem. Soc . 2011, 133, 6162.


Contact: J.-C. Berthet .

 

Maj : 15/04/2016 (2072)

 

Retour en haut