68193-40-8

Usage

Uses

Used in Chemical Catalysts Industry:
DIMETHYLBIS(T-BUTYLCYCLOPENTADIENYL)ZIRCONIUM is used as a catalyst for its high reactivity and stability, facilitating the olefin polymerization reactions that are essential in the production of a wide range of polymeric materials.
Used in Specialty Chemicals Production:
This organometallic compound is also utilized as a catalyst in the synthesis of specialty chemicals, where its unique properties contribute to the creation of complex and high-value chemical products.
Used in Pharmaceutical Industry:
DIMETHYLBIS(T-BUTYLCYCLOPENTADIENYL)ZIRCONIUM is employed in the production of pharmaceuticals, where its catalytic properties aid in the synthesis of complex drug molecules, enhancing the efficiency and selectivity of the chemical reactions involved in drug manufacturing processes.

Upstream product

• 917-54-4 methyllithium 

Downstream Products

• 100581-50-8 (Me3CCp)2Zr(μ-O)Zr(CH3)(CpCMe3)2 
• 1391997-00-4 [(Cp-tBu)2Zr(η2-CH2NMePh)][B(C6F5)4] 
• 168841-12-1 ((CH₃)3CC₅H₄)2ZrCH₃⁽¹⁺⁾*CH₃B(C₆F₅)3^(1-)=[((CH₃)3CC₅H₄)2ZrCH₃][CH₃B(C₆F₅)3] 

Relevant academic research and scientific papers

An NMR study on the reaction of substituted dimethyl zirconocenes with dimethylanilinium borate

The reaction of a series of dimethyl zirconocenes [Me2Si(Cp) 2ZrMe2, 1; Cpt-bu2ZrMe2, 2; Cpn-bu2ZrMe2, 3; Ind2ZrMe 2, 4; CpMe42ZrMe2, 5; Cp 2ZrMe2, 6] with [HNMe2Ph][B(C6F 5)4] was investigated by means of NMR spectroscopy. It was found that protonolysis of a Zr-Me group occurred generating a coordinative vacancy at the metal center and methane. Cations coming from 1-4 dimethyl precursors bound NMe2Ph, liberated from the protonation process, and formed zirconaaziridinium ion pairs {[Me2Si(Cp)2Zr(η 2-CH2NMePh)][B(C6F5)4], 7; [Cpt-bu2Zr(η2-CH2NMePh)] [B(C6F5)4], 8; [Cpn-bu 2Zr(η2-CH2NMePh)][B(C6F 5)4], 9; [Ind2Zr(η2-CH 2NMePh)][B(C6F5)4], 10}, reasonably as a consequence of CH activation of one Me group of coordinated NMe 2Ph and methane elimination. The intramolecular/interionic structures and dynamics of 7-10 ion pairs were investigated by 1H, 13C and 19F 1D-and 2D-NMR techniques. The reactions of 7 and 10 ion pairs with 2-methyl-1-heptene afforded stable diastereoisomeric ion pairs bearing a five-member azametallacycle.

Zirconium-91 chemical shifts and line widths as indicators of coordination geometry distortions in zirconocene complexes

91Zr NMR chemical shifts and line widths (Δυ1/2) are reported for a number of ring-bridged and ring-substituted zirconocene dichloride, dibromide, and dimethyl complexes. Ab initio computations at the SCF level employing basis sets of moderate size suggest that the magnitude of the electric field gradient (EFG) at the Zr atom dominates Δυ1/2 when the substituents X at Zr are varied (X = Br, Cl, Me). Substituents at the cyclopentadiene (Cp) rings affect the computed EFGs much less; in these cases, the line widths Δυ1/2 are governed by the molecular correlation times τc, which were obtained for several zirconocene dichlorides from T1(13C) measurements. Experimental trends in δ(91Zr) of zirconocenes are well reproduced computationally with the IGLO (individual gauge for localized orbitals) or GIAO (gauge including atomic orbitals) SCF methods employing large basis sets. Model calculations suggest that δ(91Zr), as well as the EFG, are quite sensitive to the inclination and twist angles of the Cp rings and, to a lesser extent, to the CpZrCp′ angle. A substantial deshielding, δ(91Zr) ca. 700 ppm, is predicted for (C5H5)2ZrMe+, presumably the active olefin-polymerizing catalyst.

Stereochemical nonrigidity in metallocenium ions

Dynamic NMr spectrscopy of the MeB(C6F5)3- salts of a series of ring-substituted zirconium- and hafnium-containing metallocenium ions, exemplified by (RCp)2ZrCH3+, reveals two exchange processes.One, having the lower free energy of activation, involves shift of the CH3 group from one lateral equatorial orbital to the other.The second results from exchange between the metal-CH3 and B-CH3 groups.Effects of structural variations on exchange barriers are discussed and related to metallocenium ion-catalyzed olefin polymerization.Keywords: Metallocenium ions; Stereochemical nonrigidity; Zirconium; Hafnium

Hindered η-cyclopentadienyl-metal rotation caused by lateral interaction of Cp-bonded substituents at chalcogen-bridged binuclear bent metallocene complexes [(RCp)2ZrX]2

(η-Butadiene)bis(η-tert-butylcyclopentadienyl)zirconium reacts with elemental tellurium to give [(Me3CCp)2Zr(μ-Te)]2 (6). Upon controlled hydrolysis, one bridging tellurium is exchanged for oxygen to give the metallacyclic complex [(Me3CCp)2Zr]2(μ-O)(μ-Te) (7). The analogous oxygen/selenium-bridged bimetallic zirconium complex [(Me3CCp)2Zr]2(μ-O)(μ-Se) (8) is formed upon photolysis of the μ-oxo precursor (Me3CCp)2Zr(CH3)OZr(CH3)(CpCMe 3) in the presence of a suspension of elemental selenium. Complex 6 exhibits a nearly square-planar array of alternating zirconium and tellurium atoms. In contrast, the planar ZrTeZrO framework of 7 is characterized by very different bond angles at tellurium (average 72.1 (1)°) and oxygen (average 119.2 (2)°), bringing the zirconium atoms (average Zr?Zr = 3.390 (1) A?) more closely together than in 6 (Zr?Zr = 4.067 (1) A?). In the crystal each (Me3CCp)2Zr subunit is chiral, favoring a nearly C2-symmetric conformation. The bulky tert-butyl groups are oriented trans to each other in the lateral sectors of the Cp-substituted bent metallocene unit. Combination of the two chiral (Me3CCp)2Zr moieties can give rise to the formation of two diastereomeric bis(metallocene) complexes. For the bis-(tellurium)-bridged compound 6 an achiral C2h-symmetric meso form is favored, while the oxygen, tellurium-bridged analogue 7 adopts a chiral nearly C2-symmetric conformation in the solid state. Complex 7 crystallizes in the monoclinic space group Cc with cell constants a = 18.231 (5) A?, b = 18.186 (6) A?, c = 22.563 (6) A?, β = 107.57 (2)°, V = 7132 (3) A?3, Z = 8, and R(F) = 4.08%. The [(Me3CCp)2Zr](μ-X)(μ-Y) complexes feature hindered (Me3CCp)-metal rotation in solution. Activation barriers ΔG?rot ≈ 9.6 ± 0.4 kcal/mol (for 7 at 206 K) and 11.0 ± 0.4 kcal/mol (for 8 at 222 K) have been estimated by dynamic 1H NMR spectroscopy. Complexes 7 and 8 appear to be the first examples where hindered (RCp)-M rotation is induced by a lateral (RCp)?(RCp) interaction across a rigid metal complex framework.

SYNTHESE ET REACTIVITE DE NOUVEAUX DIHYDRUROZIRCONOCENES ET-HAFNOCENES SUBSTITUES ACHIRAUX ET CHIRAUX

Hydrogenolysis of (M(CH3)2) (M=Zr, Hf) bonds gives new racemic and optically active substituted zirconocene and hafnocene dihydrides A: (RCp)2MH2 (M=Zr, Hf; R=Me, Me2CH, Me3C, PhCH2) and B: (R*Cp)2MH2 (M=Zr, Hf; R*=MeCHEtCH2, PhCHEtCH2), R*CpCpHfH2 (R*=PhCHCH3).Substitution of hydridic hydrogens by halogens, mobile hydrogen compounds, addition with unsaturated derivatives are studied.The A and B type complexes are good catalysts in hydrogenation of alkenes; the B type complexes give only poor asymmetric induction in catalytic reduction of prochiral alkenes.