A Weak Interaction between Iron and Uranium in Uranium Alkyl Complexes Supported by Ferrocene Diamide Ligands

Abstract

Alkyl complexes of uranium supported by ferrocene diamide ligands are described along with the corresponding cationic species. Synthesis of uranium dialkyl compounds fc(NSi t BuMe 2 ) 2 UR 2 [R ) Np (neo-pentyl), Bz (benzyl)] was accomplished by salt metathesis between fc(NSi t BuMe 2 ) 2 UI 2 (THF) and neo-pentyl lithium or benzyl potassium. Protonation of one alkyl ligand led to the isolation of a cationic uranium alkyl complex. DFT calculations and X-ray crystallography data support the existence of a donor-acceptor, weak interaction between iron and uranium.

Oxo Ligand Substitution in a Cationic Uranyl Complex: Synergistic Interaction of an Electrophile and a Reductant

“…The 31 P{ 1 H} NMR spectrum of 1 does not feature any resonances, possibly because they are too broad to be observed. In addition, the near-IR spectrum for 1 is similar to those of other U(IV) complexes ( Figure S30), 9,10,28,29 supporting the presence of a 5f 2 ion.…”

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.…”

P4 Activation by Lanthanum and Lutetium Naphthalene Complexes Supported by a Ferrocene Diamide Ligand

“…[16] We previously proposed that the electron-rich iron in the ferrocenebased ligand could serve as a Lewis base to a highly Lewis acidic rare-earth metal centre. [15,[17][18][19][20][21] This Lewis acid-base interaction is weak and may be disrupted by strong Lewis bases such as THF, as was the case in Y2-naph, where the extra THF molecule cancelled the weak M-Fe interaction and resulted in a long Y-Fe distance. However, in the case of La2-naph, the La-Fe interaction is maintained even with one extra THF molecule coordinated to lanthanum.…”