*** Welcome to piglix ***

Zirconocene dichloride

Zirconocene dichloride
Zirconocene-dichloride-2D-skeletal.png
Zirconocene-dichloride-from-xtal-3D-balls.png
Identifiers
3D model (Jmol)
ChemSpider
ECHA InfoCard 100.013.697
PubChem CID
Properties
C10H10Cl2Zr
Molar mass 292.31 g·mol−1
Appearance white solid
Soluble (Hydrolysis)
Hazards
Safety data sheet CAMEO Chemicals MSDS
Related compounds
Related compounds
Titanocene dichloride
Hafnocene dichloride
Vanadocene dichloride
Niobocene dichloride
Tanatalocene dichloride
Tungstenoocene dichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references

Zirconocene dichloride is an organozirconium compound composed of a zirconium central atom, with two cyclopentadienyl and two chloro ligands. It is a colourless diamagnetic solid that is somewhat stable in air.

Zirconocene dichloride may be prepared from zirconium(IV) chloride-THF complex and sodium cyclopentadienide:

The closely related compound Cp2ZrBr2 was first described by Birmingham and Wilkinson.

The compound is a bent metallocene: the Cp rings are not parallel, the average Cp(centroid)-M-Cp angle being 128°. The Cl-Zr-Cl angle of 97.1° is wider than in niobocene dichloride (85.6°) and molybdocene dichloride (82°). This trend helped to establish the orientation of the HOMO in this class of complex.

Zirconocene dichloride reacts with lithium aluminium hydride to give Cp2ZrHCl Schwartz's reagent:

Since lithium aluminium hydride is a strong reductant, some over-reduction occurs to give the dihydrido complex, Cp2ZrH2; treatment of the product mixture with methylene chloride converts it to Schwartz's reagent.

Zirconocene dichloride can also be used to prepare the Negishi reagent, Cp2Zr(η2-butene) which is used as a source for Cp2Zr in oxidative cyclisation reactions. This reagent is prepared by treating zirconacene dichloride with n-BuLi leading to replacement of the two chloride ligands with butyl. The dibutyl compound subsequently undergoes beta-hydrogen abstraction to give one η2-butene ligand, eliminating the other butyl ligand as butane.


...
Wikipedia

...