Hafnocene dichloride

Hafnocene dichloride

Names
Other names bis(cyclopentadienyl)hafnium dichloride
Identifiers
CAS Number	12116-66-4
3D model (JSmol)	Interactive image
ChemSpider	10654717
ECHA InfoCard	100.031.967
EC Number	235-177-5
PubChem CID	24942143
InChI InChI=1S/2C5H5.2ClH.Hf/c2*1-2-4-5-3-1;;;/h2*1-3H,4H2;2*1H;/q2*-1;;;+4/p-2 Key: IXKLRFLZVHXNCF-UHFFFAOYSA-L
SMILES C1C=CC=[C-]1.C1C=CC=[C-]1.[Cl-].[Cl-].[Hf+4]
Properties
Chemical formula	C10H10Cl2Hf
Molar mass	379.58 g·mol−1
Appearance	white solid
Melting point	230–233 °C (446–451 °F; 503–506 K)
Hazards
GHS labelling:[1]
Pictograms
Signal word	Danger
Hazard statements	H314, H315, H319, H335
Precautionary statements	P260, P261, P264, P264+P265, P271, P280, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P351+P338, P305+P354+P338, P316, P319, P321, P332+P317, P337+P317, P362+P364, P363, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Hafnocene dichloride is the organohafnium compound with the formula (C₅H₅)₂HfCl₂. It is a white solid that is sparingly soluble in some organic solvents. The lighter homologues zirconacene dichloride and titanocene dichloride have received much more attention. While hafnocene is only of academic interest, some more soluble derivatives are precatalysts for olefin polymerization. Moreso than the Zr analogue, this compound is highly resistant to reduction.

It is prepared by a salt metathesis reaction from hafnium tetrachloride by salt metathesis:

2 NaC₅H₅ + HfCl₄ → (C₅H₅)₂HfCl₂ + 2 NaCl