Ferrocenium tetrafluoroborate

Ferrocenium tetrafluoroborate is an organometallic compound with the formula [Fe(C₅H₅)₂]BF₄. This salt is composed of the cation [Fe(C₅H₅)₂]⁺ and the tetrafluoroborate anion (BF⁻
₄). The related hexafluorophosphate is also a popular reagent with similar properties. The ferrocenium cation is often abbreviated Fc⁺ or Cp₂Fe⁺. The salt is deep blue in color and paramagnetic. Ferrocenium salts are sometimes used as one-electron oxidizing agents, and the reduced product, ferrocene, is inert and readily separated from ionic products. The ferrocene–ferrocenium couple is often used as a reference in electrochemistry. The standard potential of ferrocene-ferrocenium is dependent on specific electrochemical conditions.^[2]

Ferrocenium tetrafluoroborate

Names
IUPAC name Ferrocenium tetrafluoroborate
Identifiers
CAS Number	1282-37-7 Y
3D model (JSmol)	Interactive image
ChemSpider	69007671
ECHA InfoCard	100.156.161
EC Number	627-836-4
PubChem CID	124204127 charge error
CompTox Dashboard (EPA)	DTXSID90746541
SMILES C1=C[CH-]C=C1.[Fe+3].C2=C[CH-]C=C2.F[B-](F)(F)F
Properties
Chemical formula	C10H10BFeF4
Molar mass	272.84 g/mol
Appearance	dark blue powder
Melting point	178 °C (352 °F; 451 K) (decomposes)
Solubility in acetonitrile	Soluble[citation needed]
Hazards[1]
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P280, P305+P351+P338, P310
Safety data sheet (SDS)	External MSDS
Related compounds
Related compounds	Ferrocene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation

Commercially available, this compound may be prepared by oxidizing ferrocene typically with ferric salts followed by addition of fluoroboric acid.^[2] A variety of other oxidants work well also, such as nitrosyl tetrafluoroborate.^[3] Many analogous ferrocenium salts are known.^[4]

Structure

According to X-ray crystallography, the structures of the metallocene component of FcBF₄ and the parent ferrocene are very similar. The Fe-C distances in the cation are 209.5 pm, about 2% longer than the Fe-C distances in ferrocene. ^[5]

References

1. "Ferrocenium tetrafluoroborate 482358". Sigma-Aldrich.
2. Connelly, N. G.; Geiger, W. E. (1996). "Chemical Redox Agents for Organometallic Chemistry". Chemical Reviews. 96 (2): 877–910. doi:10.1021/cr940053x. PMID 11848774.
3. Nielson, Roger M.; McManis, George E.; Safford, Lance K.; Weaver, Michael J. (1989). "Solvent and electrolyte effects on the kinetics of ferrocenium-ferrocene self-exchange. A reevaluation". J. Phys. Chem. 93 (5): 2152. doi:10.1021/j100342a086.
4. Le Bras, J.; Jiao, H.; Meyer, W. E.; Hampel, F.; Gladysz, J. A. (2000). "Synthesis, Crystal Structure, and Reactions of the 17-Valence-Electron Rhenium Methyl Complex [(η⁵-C₅Me₅)Re(NO)(P(4-C₆H₄CH₃)₃)(CH₃)]⁺ B(3,5-C
   ₆H
   ₃(CF
   ₃)
   ₂)⁻
   ₄: Experimental and Computational Bonding Comparisons with 18-Electron Methyl and Methylidene Complexes". J. Organomet. Chem. 616: 54–66. doi:10.1016/S0022-328X(00)00531-3.
5. Scholz, Stefan; Scheibitz, Matthias; Schödel, Frauke; Bolte, Michael; Wagner, Matthias; Lerner, Hans-Wolfram (2007). "Difference in Reactivity of Triel Halides EX₃ Towards Ferrocene". Inorganica Chimica Acta. 360 (10): 3323–3329. doi:10.1016/j.ica.2007.03.049.