2-(Dicyanomethylene)croconate
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| Names | |
|---|---|
| Preferred IUPAC name  4-(Dicyanomethylene)-3,5-dioxo-1-cyclopentene-1,2-diolate  | |
| Identifiers | |
3D model (JSmol)   |  |
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| Properties | |
| C8N2O42− | |
| Molar mass | 188.099 g·mol−1 | 
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).   Infobox references   | |
2-(Dicyanomethylene)croconate is a divalent anion with chemical formula C
8N
2O2−
4 or ((N≡C−)2C=)(C5O4)2−.  It is one of the pseudo-oxocarbon anions, as it can be described as a derivative of the croconate oxocarbon anion C
5O2−
5 through the replacement of one oxygen atom by a dicyanomethylene group =C(−C≡N)2. 
The anion was synthesized and characterized by A. Fatiadi in 1980, by hydrolysis of croconate violet treated with potassium hydroxide.[1] It gives an orange solution in water.
See also
- Croconate violet, 1,3-bis(dicyanomethylene)croconate
 - Croconate blue, 1,2,3-tris(dicyanomethylene)croconate
 - 1,2-Bis(dicyanomethylene)squarate
 - 1,3-Bis(dicyanomethylene)squarate
 
References
- ^ Alexander J. Fatiadi (1980), "Pseudooxocarbons. Synthesis of 1,2,3-tris(dicyanomethylene)croconate salts. A new bond-delocalized dianion, croconate blue". Journal of Organic Chemistry volume 45, pages 1338–1339. doi:10.1021/jo01295a044
 
