First example of a neutral homoleptic uranium alkyl. Synthesis, properties, and structure of U[CH(SiMe3)2]3

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

“…This is very close to the values reported for the parent [U{N (SiMe 3 ) 2 } 3 ] (the solid-state m eff is 3.07 m B at 300 K) [7,37,57], and only slightly higher than that measured above for the 5f 2 [U{N (SiMe 2 H) 2 } 4 ], but the range of room temperature magnetic moments of U III ( 4 I 9/2 ground state) and U IV ( 3 H 4 ground state) coordination complexes are know to have considerable overlap, and the values reported for both of these new uranium amides are within this range [58e60].…”

Characterisation of Alkane σ‐Complexes

“…46 With distances ranging from 2.12 to 2.71 Å between the alkane ligands and the tert ‐butyl groups present on the aryl oxide ligands, the notion of lipophilic interaction is supported. As with the iron(II)–porphyrinato complex discussed above, the distance between the closest approaching alkane carbon atom ( neo ‐hexane) and the uranium(III) centre ( r UC =3.73 Å) was considerably more than a conservative estimate for the sum of the U‐H‐C covalent radii (Σ UHHC =3.34 Å)118 and CU distances in related uranium(III) agostic examples,122 but well within the van der Waals radii of U⋅⋅⋅HC (Σ U⋅⋅⋅HC =4.98 Å) 116. It was also found that preference for alkane molecules to reside in the vacant cavity followed the order neo ‐hexane> cyclo‐ alkanes> n ‐pentane, suggesting that alkane coordination preference may be based on the alkane molecules’ ability to effectively occupy the vacant cavity rather than the uranium’s preference to bind to methylene or methyl groups, as is seen with transition‐metal–alkane σ‐complexes in solution, although an η 2 ‐ C,H binding mode is observed in agreement with NMR studies 29.…”

Some highlights from the development and use of bulky monodentate ligands

“…9) lanthanides LaR 3 [133], or actinides, UR 3 (Sattelberger) [134], the first stable germanium, tin or lead compounds analogous to alkenes R 2 MMR 2 (M = Ge, Sn or Pb), Lappert [135] (Fig. 10) the first persistent or stable radical derivatives of germanium tin ð _ MR 3 Þ [136], phosphorus or arsenic: _ MR 2 [106], and the first structurally authenticated Al-Al bond in a stable molecular compound in R 2 AlAlR 2 by Uhl [137] (Fig.…”