Structures of Homoleptic Benzyl Derviatives of Zirconium

Abstract

Crystals of Zr(p-CH 2 C 6 H 4 CMe 3 ) 4 , tetra(4-tert-butylbenzyl)zirconium (1), have been studied by X-ray diffraction. The crystals belong to the tetragonal system, space group I4 Å , with a = 16.481 (2), c = 7.131 (4) A Ê , so that chemically equivalent ligands are also structurally equivalent, unlike other known homoleptic M(CH 2 -C 6 H 5 ) 4 compounds. ZrÐCH 2 ÐC ipso bond angles of 90.0 (2) suggest that ligands are 2 -bonded. The structure is discussed along with that of Zr(CH 2 C 6 H 5 ) 4 , tetrabenzylzirconium (2) (redetermined), which is crystallographically unsymmetrical but also of approximate S 4 symmetry. The distortion of (2) from tetragonal symmetry (the four ZrÐCH 2 ÐC ipso bond angles being rather different) is discussed along with crystal packing.

The Effects of Activators on Zirconium Phosphinimide Ethylene Polymerization Catalysts

“…The corresponding Zr−C−C ipso angle is 90.93(18)° . Similar η 2 -interactions have been reported in the compounds Zr(O-2,6 -t -Bu 2 C 6 H 3 )Bn 3 , Zr(C 5 H 4 (RMe 2 CH 2 Ph))Bn 3 (R = C, Si 23 ), Zr(CH 2 C 6 H 4 p - t -Bu) 4 , and Cp*HfBn 3 . The Zr−N distance of 1.951(2) Å and the Zr−N−P angle of 171.84(13)° are similar to those seen in dichloride analogues above.…”

Identity and relationships are central to the construction of patient centred care

“…The Zr atom displays a square pyramidal geometry with the tridentate ligand and one methyl group at the base of the pyramid, whereas the apical position is occupied by an η 3 ‐indolyl unit belonging to the other unit (Zr1C34 2.574(6) Å, Zr1C33 2.633(6) Å, Zr1C35 2.699(6) Å) 28. Similar coordination modes were also observed by Y. Yang et al.…”

Single-Site Organozirconium Catalyst Embedded in a Metal–Organic Framework

“…20 The optimum fit around Zr was obtained with one Zr−Bn ligand and three Zr−O ligands. The derived Zr−C bond length is identical to that in ZrBn 4 , 2.29 Å; 21 while the Zr−O bonds are slightly shorter than those in ZrO 2 , 2.13 and 2.15 Å, respectively. 22 Organozirconium precursor−MOF interactions were next modeled using DFT.…”