ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
A New Synthesis and the Crystal Structure Analysis of “Croconate Blue”, 1,2,4-Tris(dicyanomethylene)croconateReaction of the croconic acid diamide 9 with malononitrile in methanol leads to the condensation product 10, in which the two dimethylamino groups can be replaced by the anion of malononitrile to yield the potassium salt of the pseudooxocarbon dianion, so-called “Croconate Blue” 11a. Contrary to earlier findings, the structure of 11b, proved by X-ray diffraction, shows that the dicyanomethylene substituents of the dianion are located in 1,2,4-position of the five-membered ring.
Notes:
Bei der Reaktion des Krokonsäurediamids 9 mit Malondinitril in Methanol entsteht das Kondensationsprodukt 10, dessen Dimethylaminofunktionen durch das Anion des Malondinitrils substituiert werden unter Bildung des Kaliumsalzes des Pseudooxo-kohlenstoff-Dianions 11a, des sogenannten “Krokonat-Blau”. Im Gegensat zzu früheren Befunden beweist die Röntgenstrukturanalyse von 11b, daß die Dicyanmethylen-Substituenten des Dianions in 1,2,4-Position des Fünfringsystems angeordnet sind.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19871201014
