Silver cyanate
Structural formula | ||||||||||||||||
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General | ||||||||||||||||
Surname | Silver cyanate | |||||||||||||||
other names |
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Molecular formula | AgOCN | |||||||||||||||
Brief description |
beige to gray powder |
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properties | ||||||||||||||||
Molar mass | 149.88 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
4.0 g cm −3 (25 ° C) |
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safety instructions | ||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Silver cyanate is the cyanate salt of silver with the formula AgOCN; it is isomeric with silver fulminate (AgONC), the salt of acidic acid . Justus Liebig and Friedrich Wöhler discovered isomerism in these two connections in the 1820s .
Extraction and presentation
Silver cyanate can be obtained by reacting potassium cyanate or urea with silver nitrate .
The second reaction equation corresponds to the reverse reaction of the first synthesis of urea in 1828 by Friedrich Wöhler.
properties
Silver cyanate is a beige to gray powder. It crystallizes in the monoclinic crystal system in the space group P 2 1 / m with the lattice parameters a = 547.3 pm , b = 637.2 pm, c = 341.6 pm and β = 91 °. In the unit cell contains two formula units . According to this crystal structure, the nitrogen atoms of the cyanate anion bridge two silver atoms, resulting in a zigzag chain with linearly coordinated silver atoms. The Ag-N distance is 211.5 pm. The oxygen atoms coordinate only weakly with the silver atoms of the next zigzag chain. The Ag-O distance is correspondingly long at 299.6 pm. For comparison: the Ag-O distance in silver (I) oxide is 205 pm.
Silver cyanate is decomposed by the action of acids, producing carbon dioxide and the corresponding ammonium salt:
Individual evidence
- ↑ a b c d data sheet Silver cyanate, 99% from Sigma-Aldrich , accessed on December 13, 2011 ( PDF ).
- ↑ Willy Kühne: Textbook of Physiological Chemistry . 1868 ( page 470 in the Google book search).
- ^ D. Britton, JD Dunitz: The crystal structure of silver cyanate , Acta Cryst. (1965). 18, 424-428, doi : 10.1107 / S0365110X65000944
- ^ LE Sutton: Interatomic Distances. , London: The Chemical Society (1958).
- ↑ J. Milbauer: Determination and separation of cyanates, cyanides, rhodanides and sulfides in Fresenius' Journal of Analytical Chemistry 42 (1903) 77-95, doi : 10.1007 / BF01302741 .