2-(Dicyanomethylene)croconate explained

2-(Dicyanomethylene)croconate is a divalent anion with chemical formula 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 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

Notes and References

1. 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.