Silver cyanide

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Silver cyanide
Image:Silver cyanide.jpg
IUPAC name	Silver cyanide
Other names	Argentous cyanide
Identifiers
CAS number	[506-64-9]
RTECS number	VW3850000
Properties
Molecular formula	CNAg
Molar mass	133.89 g/mol
Appearance	colorless, gray (impure)
Density	3.95 g/cm³, solid
Melting point	320 °C
Solubility in water	insoluble
Solubility in other solvents	insol.
Structure
Coordination geometry	linear
Hazards
Main hazards	toxic
R-phrases	25-32-33-41-50/53
S-phrases	7-26-45-60-61
Related compounds
Related compounds	AgCl NaCN Copper(I) cyanide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Silver cyanide is the chemical compound with the formula AgCN. This colorless solid forms upon treatment of solutions containing Ag⁺ with cyanide. This precipitation step is used in some schemes to recover silver from solution. Its structure consist of chains with the connectivity Ag-C≡N-Ag-C≡N-, etc. Two-coordination is typical of silver, and cyanide is well known to bridge transition metals, as illustrated by the more famous case of Prussian Blue.

AgCN precipitates upon the addition of sodium cyanide to a solution containing Ag⁺. The precipitate dissolves upon the addition of further amounts of cyanide or other ligands such as tertiary phosphines.

Silver cyanides form structural complex materials upon reaction with other anions.^[1] Some silver cyanides are luminescent.^[2]

[edit] References

^ Urban, V.; Pretsch, T.; Hartl, H. “From AgCN Chains to a Fivefold Helix and a Fishnet-Shaped Framework Structure” Angewandte Chemie International Edition 2005, volume 44, pages 2794 – 2797.
^ Omary, M. A.; Webb, T.R.; Assefa, Z.; Shankle, G. E.; Patterson, H. H. “Crystal Structure, Electronic Structure, and Temperature-Dependent Raman Spectra of Tl[Ag(CN)₂]: Evidence for Ligand-Unsupported Argentophilic Interactions” Inorganic Chemistry 1998, volume 37, pages 1380-1386.