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 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 0.400 V vs. the normal hydrogen electrode (NHE)[2] and is often assumed to be invariant between different solvents.
|  | |
|  | |
|  | |
| Names | |
|---|---|
| Other names dicyclopentadienyl iron tetrafluoroborate | |
| Identifiers | |
| 3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.156.161 | 
| PubChem CID | 
 | 
| CompTox Dashboard (EPA) | |
| 
 | |
| Properties | |
| C10H10BFeF4 | |
| Molar mass | 272.84 g/mol | 
| Appearance | dark blue powder | 
| Melting point | 178 °C (352 °F; 451 K) (decomposes) | 
| Solubility in acetonitrile | Soluble | 
| Hazards[1] | |
| GHS labelling: | |
|  | |
| Danger | |
| H314 | |
| 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). Infobox references | |
Preparation
    
Commercially available, this compound may be prepared by oxidizing ferrocene typically with ferric salts followed by addition of fluoroboric acid.[3] A variety of other oxidants work well also, such as nitrosyl tetrafluoroborate.[4] Many analogous ferrocenium salts are known.[5]
References
    
- "Ferrocenium tetrafluoroborate 482358". Sigma-Aldrich.
- Bard, A.J.; Parsons, R.; Jordan, J. (1985). Standard Potentials in Aqueous Solution. New York: IUPAC.
- 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.
- 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.
-  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.

