3D model (Jmol)
|Molar mass||145.865 g/mol|
|Appearance||white or grey crystalline powder, hygroscopic|
|Melting point||690 °C (1,274 °F; 963 K)|
|Boiling point||700 °C (1,292 °F; 973 K) (decomposes)|
|Main hazards||toxic, reacts violently
with water, powerful oxidizer
|Safety data sheet||MSDS|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
As a strong fluorinating agent, AgF2 should be stored in Teflon or a passivated metal container. It is light sensitive.
AgF2 can be purchased from various suppliers, the demand being less than 100 kg/year. While laboratory experiments find use for AgF2, it is too expensive for large scale industry use. In 1993, AgF2 cost between 1000-1400 US dollars per kg.
Composition and structure
AgF2 is a white crystalline powder, but it is usually black/brown due to impurities. The F/Ag ratio for most samples is < 2, typically approaching 1.75 due to contamination with Ag and oxides and carbon.
For some time, it was doubted silver was actually in the +2 oxidation state rather in some combination of states such as AgI[AgIIIF4], which would be similar to silver(I,III) oxide. Neutron diffraction studies, however, confirmed its description as silver(II). The AgI[AgIIIF4] was found to be present at high temperatures, but it was unstable with respect to AgF2.
In the gas phase, AgF2 is believed to have D∞h symmetry.
AgF2 is a strong fluorinating and oxidising agent. It is formed as an intermediate in the catalysis of gaseous reactions with fluorine by silver. With fluoride ions, it forms complex ions such as AgF−
3, the blue-violet AgF2−
4, and AgF4−
It is used in the fluorination and preparation of organic perfluorocompounds. This type of reaction can occur in three different ways (here Z refers to any element or group attached to carbon, X is a halogen):
- CZ3H + 2 AgF2 → CZ3F +HF + 2 AgF
- CZ3X + 2AgF2 → CZ3F +X2 + 2 AgF
- Z2C=CZ2 + 2 AgF2 → Z2CFCFZ2 + 2 AgF
- C6H6 + 2 AgF2 → C6H5F + 2 AgF + HF
- 2 AgF2 + Xe → 2 AgF + XeF2
- 2 AgF2 + CO → 2 AgF + COF2
It reacts with water to form oxygen gas:
- 4 AgF2 + 4 H2O → 2 Ag2O + 8 HF + O2
2 is a very strong oxidizer that reacts violently with water, reacts with dilute acids to produce ozone, oxidizes iodide to iodine, and upon contact with acetylene forms the contact explosive silver acetylide. It is light-sensitive, very hygroscopic and corrosive. It decomposes violently on contact with hydrogen peroxide, releasing oxygen gas. It also liberates HF, F
2, and elemental silver.
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