Synthesis and Structure of the Bis(tetramethylcyclopentadienyl)uranium Metallocenes (C₅Me₄H)₂UMe₂, (C₅Me₄H)₂UMeCl, [(C₅Me₄H)₂U][(μ-η⁶:η¹-Ph)(μ-η¹:η¹-Ph)BPh₂], and [(C₅Me₄)SiMe₂(CH₂CHCH₂)]₂UI(THF)

Two-electron reductive reactivity of trivalent uranium tetraphenylborate complexes of (C5Me5)1− and (C5Me4H)1−

“…The bonding parameters are normal for eight-coordinate tetravalent uranium complexes. For example, the 2.443 Å average U-(C 5 Me 4 H ring centroid) distance is similar to the 2.444, 2.429, and 2.42 Å distances in (C 5 Me 4 H) 2 UMe 2 [9], (C 5 Me 4 H) 2 UMeCl [9], and (C 5 Me 4 H) 2 UCl 2 [9], respectively. The 2.691(6) Å average U-S distance in 4 is equivalent to the 2.687(2)-2.700(2) Å U-S distances in the bis(dithiolene) complex [Na (18-…”

“…Apparently, this two-electron reduction reactivity for the (BPh 4 ) 1À /U 3+ combination is not connected with some special aspect of the (C 5 Me 5 ) 1À complexes. This contrasts with the sterically induced reduction chemistry of (C 5 Me 5 ) 3 M compounds [6] which does not occur with the less sterically crowded (C 5 Me 4 H) 3 M analogs [9,28,29].…”

“…Accordingly, the reductive reactivity of the tetramethylcyclopentadienyl complex [(C 5 Me 4 H) 2 U][(l-g 6 :g 1 -Ph)(l-g 1 :g 1 -Ph)BPh 2 ] (2) [9] was examined. Complex 2 differs from 1 in that one phenyl group is oriented g 6 to U 3+ and the other is g 1 , whereas 1 has two g 2 -phenyl groups.…”

Diazoalkane Reduction for the Synthesis of Uranium Hydrazonido Complexes

“…Following refinement of the data, compound 4 is assigned as the uranium(IV) metallacycle Tp* 2 U-N(N=CHSiMe 3 )CH=CPh (4) (Figure 1, Table 1), which features an eight-coordinate uranium atom in a distorted square-antiprismatic geometry. [19,[45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62] This is most likely due to increased s character at the U-C44 bond as a result of multiple bonding at the adjacent carbon-carbon bond (C44-C45). The resulting structure of complex 4 has a U1-N41 bond length of 2.348(6) Å, indicative of a uranium(IV)-nitrogen(amide) bond.…”

Comparison of the Reactivity of 2‐Li‐C6H4CH2NMe2 with MCl4 (M=Th, U): Isolation of a Thorium Aryl Complex or a Uranium Benzyne Complex

“…Even actinide aryl complexes are rare, [8,9] and those that have been isolated often feature aryl ligands stabilized by chelating interactions.…”