Molybdocene dichloride

Molybdocene dichloride is the organomolybdenum compound with the formula (η⁵-C₅H₅)₂MoCl₂ and IUPAC name dichlorobis(η⁵-cyclopentadienyl)molybdenum(IV), and is commonly abbreviated as Cp₂MoCl₂. It is a brownish-green air- and moisture-sensitive powder. In the research laboratory, it is used to prepare many derivatives.

Molybdocene dichloride

Names
IUPAC name dichlorobis(η^5-cyclopentadienyl)molybdenum(IV)
Other names molybdocene dichloride, molybdenocene dichloride, dichloridobis(cyclopentadienyl)molybdenum(IV)
Identifiers
CAS Number	12184-22-4
3D model (JSmol)	Interactive image
ChemSpider	398274
ECHA InfoCard	100.159.644
PubChem CID	452153
CompTox Dashboard (EPA)	DTXSID10923978
InChI InChI=1S/2C5H5.2ClH.Mo/c2*1-2-4-5-3-1;;;/h2*1-5H;2*1H;/q2*-1;;;+2/p-2 Key: QGGWSCVAFKWITK-UHFFFAOYSA-L InChI=1/2C5H5.2ClH.Mo/c2*1-2-4-5-3-1;;;/h2*1-5H;2*1H;/q2*-1;;;+2/p-2/r2C5H5.Cl2Mo/c2*1-2-4-5-3-1;1-3-2/h2*1-5H;/q2*-1; Key: QGGWSCVAFKWITK-OWLYHJECAX
SMILES [cH-]1cccc1.[cH-]1cccc1.Cl[Mo+2]Cl
Properties
Chemical formula	C10H10Cl2Mo
Molar mass	297.04 g·mol^−1
Appearance	greenish-brown powder
Solubility in water	insoluble, moisture sensitive
Hazards
Safety data sheet	[1]
Related compounds
Related compounds	Ferrocene Zirconocene dichloride Vanadocene dichloride Niobocene dichloride Titanocene dichloride Tantalocene dichloride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Preparation and structure

The compound is prepared from molybdocene dihydride by treatment with chloroform:[2]

(C₅H₅)₂MoH₂ + 2 CHCl₃ → (C₅H₅)₂MoCl₂ + 2 CH₂Cl₂

The compound adopts a "clamshell" structure where the Cp rings are not parallel, the average Cp(centroid)-M-Cp angle being 130.6°. The two chloride ligands are cis, the Cl-Mo-Cl angle of 82° being narrower than in niobocene dichloride (85.6°), which in turn is less than in zirconacene dichloride (92.1°). This trend helped to establish the orientation of the HOMO in this class of complex.[3]

Uses

Unlike the titanocene and zirconacene derivatives, the molybdocene compounds have yielded no commercial applications.

All metallocene dihalides exhibit some anti-cancer activity,[4] but these have not yielded useful compounds in the clinic.[5]

References

1. "42-0100 Molybdenum " Bis(cyclopentadienyl)molybdenum dichloride, 99%". Strem Chemicals. 27 July 2011. Retrieved 5 February 2012.
2. Silavwe, Ned D.; Castellani, Michael P.; Tyler, David R. (1992). "Bis(η5-Cyclopentadienyl)Molybdenum(IV) Complexes". Inorganic Syntheses. Inorganic Syntheses. 29. pp. 204–211. doi:10.1002/9780470132609.ch50. ISBN 9780470132609.
3. K. Prout, T. S. Cameron, R. A. Forder, and in parts S. R. Critchley, B. Denton and G. V. Rees "The crystal and molecular structures of bent bis-π-cyclopentadienyl-metal complexes: (a) bis-π-cyclopentadienyldibromorhenium(V) tetrafluoroborate, (b) bis-π-cyclopentadienyldichloromolybdenum(IV), (c) bis-π-cyclopentadienylhydroxomethylaminomolybdenum(IV) hexafluorophosphate, (d) bis-π-cyclopentadienylethylchloromolybdenum(IV), (e) bis-π-cyclopentadienyldichloroniobium(IV), (f) bis-π-cyclopentadienyldichloromolybdenum(V) tetrafluoroborate, (g) μ-oxo-bis[bis-π-cyclopentadienylchloroniobium(IV)] tetrafluoroborate, (h) bis-π-cyclopentadienyldichlorozirconium" Acta Crystallogr. 1974, volume B30, pp. 2290–2304. doi:10.1107/S0567740874007011
4. Roat-Malone, R. M. (2007). Bioinorganic Chemistry: A Short Course (2nd ed.). John Wiley & Sons. pp. 19–20. ISBN 978-0-471-76113-6.
5. Waern, J. B.; Dillon, C. T.; Harding, M. M. (2005). "Organometallic Anticancer Agents: Cellular Uptake and Cytotoxicity Studies on Thiol Derivatives of the Antitumor Agent Molybdocene Dichloride". J. Med. Chem. 48 (6): 2093–2099. doi:10.1021/jm049585o. PMID 15771451.