Silver hexafluorophosphate

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Silver hexafluorophosphate
Silver hexafluorophosphate.png
Identifiers
CAS number 26042-63-7
PubChem 168464
ChemSpider 147361 YesY
Jmol-3D images Image 1
Properties
Molecular formula AgPF6
Molar mass 252.83 g/mol
Appearance Off-white powder
Melting point 102 °C (216 °F; 375 K)
Solubility in water organic solvents
Hazards
MSDS External MSDS
EU classification Corrosive (C)
R-phrases R34
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Silver hexafluorophosphate, sometimes referred to "silver PF-6," is an inorganic compound with the formula AgPF6.

Uses and reactions[edit]

Silver hexafluorophosphate is a commonly encountered reagent in inorganic and organometallic chemistry. It is commonly used to replace halide ligands with the weakly coordinating hexafluorophosphate anion; the abstraction of the halide is driven by the precipitation of the appropriate silver halide. Illustrative is the preparation of acetonitrile complexes from a metal bromide, a reaction that would typically be conducted in a solution of acetonitrile:

AgPF6 + Re(CO)5Br + CH3CN → AgBr + [Re(CO)5(CH3CN)]PF6

AgPF6 can act as an oxidant, forming silver metal as a by-product. For example, in solution in dichloromethane, ferrocene is oxidised to ferrocenium hexafluorophosphate:[1]

AgPF6 + Fe(C5H5)2 → Ag + [Fe(C5H5)2]PF6 (E = 0.65 V)

Related reagents[edit]

In terms of their properties and applications, silver tetrafluoroborate (AgBF4) and the hexafluoroantimonate (AgSbF6) are similar to AgPF6.

Comparison with silver nitrate[edit]

Silver nitrate is a traditional and less expensive halide abstraction reagent, as indicated by its widespread use in qualitative tests for halides. Relative to AgPF6, however, silver nitrate is poorly soluble in weakly basic solvents: the nitrate anion is Lewis basic and presents an interfering ligand that precludes its use in stringent applications.

References[edit]

  1. ^ Connelly, N. G.; Geiger, W. E. (1996). "Chemical Redox Agents for Organometallic Chemistry". Chem. Rev. 96: 877–922. doi:10.1021/cr940053x. PMID 11848774.