2-(Dicyanomethylene)croconate

Ion 2-dicyanomethylene croconate.svg skin-invert 2-(dicyanomethylene)croconate dianion 4-(Dicyanomethylidene)-3,5-dioxocyclopen-1-ene-1,2-bis(olate) 1S/C8H2N2O4/c9-1-3(2-10)4-5(11)7(13)8(14)6(4)12/h13-14H/p-2 correct chemspider UOFODKSWJURJDQ-UHFFFAOYSA-L correct chemspider 26234929 correct chemspider 139033599 C(#N)C(=C1C(=O)C(=C(C1=O)[O-])[O-])C#N 8 2 4 2− 2-(Dicyanomethylene)croconate is a divalent anion with chemical formula C 8 N 2 O 4 2- 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 5 O 5 2- 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.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. 10.1021/jo01295a044 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 Category:Oxyanions Category:Cyclopentenes Category:Nitriles