Names | |
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IUPAC name
Tetrakis(acetonitrile)copper(I) hexafluorophosphate
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Identifiers | |
ECHA InfoCard | 100.198.153 |
PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
[Cu(CH3CN)4]PF6 | |
Molar mass | 372.7198 g/mol |
Appearance | White powder |
Melting point | 160 °C (320 °F; 433 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Tetrakis(acetonitrile)copper(I) hexafluorophosphate is a salt with the formula [Cu(CH3CN)4]PF6. It is a colourless solid that is used in the synthesis of other copper complexes. The cation [Cu(CH3CN)4]+ is a well-known example of a transition metal nitrile complex.[1]
As confirmed by X-ray crystallographic studies, the copper(I) ion is coordinated to four almost linear acetonitrile ligands in a nearly ideal tetrahedral geometry.[2][3] Similar complexes with other anions including the perchlorate, tetrafluoroborate, and nitrate are known.[1]
The cation was first reported in 1923 with a nitrate anion as a byproduct of the reduction of silver nitrate with a suspension of copper powder in acetonitrile.[4] [Cu(CH3CN)4]PF6 is generally produced by the addition of HPF6 to a suspension of copper(I) oxide in acetonitrile:[5]
The reaction is highly exothermic, and may bring the solution to a boil. Upon crystallization, the resulting microcrystals should be white, though a blue tinge is common, indicating the presence of Cu2+ impurities.[5]
The acetonitrile ligands protect the Cu+ ion from oxidation to Cu2+, but are rather poorly bound: with other counterions, the complex forms di-[1] and tri-acetonitrilo[6] complexes and is also a useful source of unbound Cu(I).[5]
Water-immiscible organic nitriles have been shown to selectively extract Cu(I) from aqueous chloride solutions.[7] Through this method, copper can be separated from a mixture of other metals. Dilution of acetonitrile solutions with water induces disproportionation: