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2-(Dicyanomethylene)croconate

divalent anion

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionJul 22, 2026
Entity authorityQ4596817 ↗
Source-derived summary

2-(Dicyanomethylene)croconate is a divalent anion with chemical formula C8N2O2−4 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 C5O2−5 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.

Editorial summary

“2-(Dicyanomethylene)croconate” enters the record as divalent anion. Crown Archives preserves that source wording while asking what Dicyanomethylene, croconate and divalent can confirm, complicate or overturn.

Editorial reviewA practical starting point whose main value is the path it opens into stronger specialist and primary sources. The current lead gives the account dated anchors—1980—that can be checked directly. The selected authority fields contribute no independent date. Its strongest next move is a source search built around Dicyanomethylene, croconate and divalent.
Editorial analysis

Why this record matters

“2-(Dicyanomethylene)croconate” is worth following because a concise public description often conceals a longer documentary argument. Here, Dicyanomethylene, croconate and divalent provides the most credible route into that argument.

Evidence profile

Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 22, 2026. The linked authority identifier is Q4596817. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1980.

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A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

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Source & attribution

This entry incorporates text from “2-(Dicyanomethylene)croconate” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.