Tribenzyl(η⁵-pentamethylcyclopentadienyl)hafnium(IV)

Abstract

The title compound, [Hf(C7H7)3(C10H15)], adopts a monomeric three‐legged piano‐stool structure. One benzyl ligand is disordered between two sites (44:56%) related by a ∼30° rotation about an axis defined by the Hf atom and the ipso‐C atom of the benzyl ligand.

A comparative study of the reactivity of Zr(IV), Hf(IV) and Th(IV) metallocene complexes: Thorium is not a Group IV metal after all

“…Similarly, (C 5 Me 5 )Hf(CH 2 Ph) 3 (18) was prepared by reacting (C 5 Me 5 )HfCl 3 with 3 equiv. PhCH 2 MgCl [24]. However, these compounds were obtained in low to moderate yields (∼60% (15), 65% (17), 36% (18)), which may be attributed to the omission of dioxane from these synthetic procedures.…”

“…The selected metrical parameters for complex 16 compare well with those reported for the two other structurally characterized hafnium phenyl compounds, [N(SiMe 2 CH 2 PMe 2 ) 2 ]Hf(Ph)( 4 -C 4 H 6 ) (Hf-C ipso = 2.290(6)Å, C-C ipso -C = 112.7(6) • ) [26a] and [NBu 4 ][Hf(C 6 Cl 5 ) 3 Cl 2 ] (Hf-C ipso = 2.259 (13) Compound 17 also possesses a distorted tetrahedral coordination environment about the hafnium center with the two benzyl ligands situated in the metallocene wedge. The Hf(1)-C(11) (2.291(7)Å) and Hf(1)-C(18) (2.294(7)Å) bond lengths fall within the range typically observed for a hafniumbenzyl linkage (2.214(7)-2.374(9)Å) [24,27]. For example, the tris(benzyl) complexes, (C 5 H 5 B-CH 2 Ph)Hf(CH 2 Ph) 3 and (C 5 Me 5 )Hf(CH 2 Ph) 3 , have Hf CH 2 bond distances of 2.234 (3) (3), and 2.282(6)Å [24], respectively.…”

“…The Hf(1)-C(11) (2.291(7)Å) and Hf(1)-C(18) (2.294(7)Å) bond lengths fall within the range typically observed for a hafniumbenzyl linkage (2.214(7)-2.374(9)Å) [24,27]. For example, the tris(benzyl) complexes, (C 5 H 5 B-CH 2 Ph)Hf(CH 2 Ph) 3 and (C 5 Me 5 )Hf(CH 2 Ph) 3 , have Hf CH 2 bond distances of 2.234 (3) (3), and 2.282(6)Å [24], respectively. The benzyl ligands are bound to the metal center in an 1 -fashion (Hf(1)-C(12) = 3.338Å, Hf(1)-C(11)-C(12) = 120.1(5) • ; Hf(1)-C(19) = 3.304Å, Hf(1)-C(1)-C(19) = 123.3(5) • ) and display no secondary interactions between the arene ring and the hafnium metal center.…”

Crystal structure of (1,3-di-tert-butyl-η5-cyclopentadienyl)trimethylhafnium(IV)

“…The synthesis of the compound was described by Cuenca et al (1996). For the structures of related Hf IV derivatives and a comparison of Hf-C bond lengths, see: Itagaki et al (2009); Schä fer et al (2013); Shah et al (1996); Swenson et al (2000 M r = 400.89…”

Untitled

“…78 Density functional calculations have been carried out on the hexaphosphotitanocene [Ti(h 5 -C 2 P 3 Bu t 2 ) 2 ] and its photoelectron spectrum assigned. 79 [HfCp*(CH 2 Ph) 3 ] has a three-legged piano-stool structure 80 as do [Zr(guanidinate)(CH 2 Ph) 3 ] 81 and [ZrCp*(OC 6 H 3 Me 2 -2,6) 3 ]. 82 In the case of [Zr(guanidinate)(CH 2 Ph) 3 ], the structure of molecules crystallised from pentane shows only h 1 -bonded benzyls, 81 in contrast to a previous report on crystals obtained from toluene where h 2 -benzyls were reported.…”