Compositional variations in monomeric trimethylsilylated allyl lanthanide complexes

Allyl complexes of the heavy alkaline-earth metals: molecular structure and catalytic behavior

“…22 This is in line with previous observations that when bonded to electropositive metals, the allyl ligand has a nearly constant ''radius''; i.e., changes in M-C distances can be estimated from differences in the metal radii alone. 27 Even with the M-C bond length variation, the angle between the allyl planes for SrA 0 2 (thf) 2 (115.11) and CaA 0 2 (thf) 2 (115.51) is nearly identical. The angle may be controlled by the steric bulk of the trimethylsilyl substituents.…”

Advances in organometallic synthesis with mechanochemical methods

“…ScA′ 3 can be made from ScCl 3 and K[A′] in THF in approximately 60% yield, and mechanochemically in 15, 25, and 42% yield by glass flask, disperser, and planetary ball milling, respectively. 44 The same is true of HoA′ 3 and ErA′ 3 , which can be made equally well in solution 80,81 or by ball milling. 82 Some multimetallic clusters are also in this category; the 1 : 2 reactions of Au(CuCPh)PPh 3 with Ag(OTf ) or Ag(OTf )(tht) (tht = tetrahydrothiophene) lead to the high nuclearity species Ag 12 Au 10 (CuCPh) 17 (OTf ) 5 (PPh 3 ) 3 and Ag 26 Au 20 (CuCPh) 34 (OTf ) 12 (PPh 3 ) 6 (tht) 12 , respectively.…”

Complexes with Sterically Bulky Allyl Ligands: Insights into Structure and Bonding

“…[23,24,45,72] A related disordered structure was found for Y[AЈ] 3 , [73] and similar structures probably exist for Ln[AЈ] 3 (Ln = Dy, Ho, Er, Lu). [71] Monomeric structures are also found for the homoleptic tetrakis(allyl)thorium complexes Th[(SiMe 3 ) n C 3 H 5-n ] 4 (n = 1,2). [18] The thorium complexes contain four syn or syn,syn η 3 -ligands ( Figure 21); in the case of Th[1-(SiMe 3 )C 3 H 4 ] 4 , they are in a configuration with approximate S 4 symmetry.…”

“…[70] The additional steric demand of bulky allyl ligands can prevent such oligomerization; an example is the tris(η 3 -allyl) thulium complex, Tm[AЈ] 3 ( Figure 20). [71] The molecule is disordered over a threefold axis, with the ligands arranged around the metal center such that one allyl ligand is oriented roughly anti-parallel to the other two ( Figure 20). The trimethylsilyl groups are in a syn,syn configuration, as is found with other trimethylsilyl-substituted allyl lanthanide complexes.…”

“…[71] This approach is similar to one previously used with cyclopentadienyl complexes, [82][83][84] and the constant value of the radius is a measure of the ionicity of the M-L bonding (i.e., D M-L = r + + r -).…”