2-(Dicyanomethylene)croconate
# 2-(Dicyanomethylene)croconate

2-(Dicyanomethylene)croconate is a divalent anion with chemical formula C $_8N$ $_2O^{2−}$ $_4$ or $((N≡C−)_2C=)(C_5O_4)^{2−}.$ It is one of the pseudo-oxocarbon anions, as it can be described as a derivative of the croconate oxocarbon anion C $_5O^{2−}$ $_5$ 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. It gives an orange solution in water.

