In situ generation of uranium alkyl complexes

Abstract

A new method for generating uranium alkyl complexes is described. Although homoleptic uranium alkyl complexes are notoriously unstable and difficult to work with, by generating such species in situ, a wide range of alkyl complexes can be accessed from UI(3)(THF)(4).

New UIII and UIV silylamides and an improved synthesis of NaN(SiMe2R)2 (R = Me, Ph)

“…This pyramidal geometry is always seen in f-element tris(amide) complexes, such as [U{N(SiMe 3 ) 2 } 3 ] (UeN: 2.320(4) Å) [22], and can be explained for these compounds by the polarised-ion model [22]. Three Ph groups form close contacts with the uranium atom via the ipso-carbon and Si atom (U/Si: 3.319(5) Å) as has been seen in [U{N( t Bu)3,5-Me 2 C 6 H 3 } 3 (thf)] which showed slightly shorter distances (UeN: 2.295(10) to 2.361(9) Å, U/ipso C: 2.886(12) to 2.980 (12) Å), and aryl interactions are also seen in uranium(IV) benzyl compounds [54,55]. This is seen most clearly in the top view of the complex, Fig.…”

Investigation of the Electronic Structure of Mono(1,1′-Diamidoferrocene) Uranium(IV) Complexes

“…All experiments were performed under a dry nitrogen atmosphere using standard Schlenk techniques or an MBraun inert-gas glove box. Solvents were purified using a two-column solid-state purification system by the method of Grubbs 72 80 and (NN TBS )U(CH2Ph)(OAr) 37 were synthesized following previously published procedures. NMR solvents were obtained from Cambridge Isotope Laboratories, degassed, and stored over activated molecular sieves prior to use.…”

Siloxides as Supporting Ligands in Uranium(III)‐Mediated Small‐Molecule Activation

“…In spite of the highly reducing character of U III in such a strongly electron‐donating environment, complex 1 was sufficiently stable in organic solvents (a few hours at room temperature) for us to investigate its reactivity. This stability provided by siloxide coordination with respect to the disproportionation reaction and cleavage by solvents1g, 15 is quite remarkable and is attributed to the bulk of the siloxide and to the multiple binding modes, as such siloxide ligands can readily become η 2 ligands. To investigate the potential of this new U III precursor in reductive chemistry, we explored its reaction with the C1 substrates CS 2 and CO 2 , and with toluene.…”