World Library  
Flag as Inappropriate
Email this Article

Zirconocene dichloride

Article Id: WHEBN0021406108
Reproduction Date:

Title: Zirconocene dichloride  
Author: World Heritage Encyclopedia
Language: English
Subject: Titanocene dichloride, Vanadocene dichloride, Sandwich compound
Publisher: World Heritage Encyclopedia

Zirconocene dichloride

Zirconocene dichloride
CAS number 1291-32-3 YesY
PubChem 10891641
ChemSpider 29081433 N
Jmol-3D images Image 1
Molecular formula C10H10Cl2Zr
Molar mass 292.32 g mol−1
Appearance white solid
Solubility in water Soluble (Hydrolysis)
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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.

Preparation and structure

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

ZrCl4(THF)2 + 2 NaCp → Cp2ZrCl2 + 2 NaCl + 2 THF

The closely related compound Cp2ZrBr2 was first described by Birmingham and Wilkinson.[1]

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.[2]


Schwartz's reagent

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

(C5H5)2ZrCl2 + 1/4 LiAlH4 → (C5H5)2ZrHCl + 1/4 "LiAlCl4"

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.[3]

Negishi 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 alpha-elimination give one η2-butene ligand, eliminating the other butyl ligand as butane.[4]


Further reading

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.