cis-Aconitic Acid at 150K

cis-Aconitic acid (cis-1-propene-1,2,3-tricarboxylic acid, C₆H₆O₆, crystallizes with an intramolecular hydrogen bond between the two carboxylic acid groups linked by the C=C double bond and exhibits a complex intermolecular hydrogen-bond pattern. The two carboxylic acid groups involved in the intramolecular hydrogen bond are coplanar with the propene skeleton, while the third carboxylic group is twisted out of this plane with a dihedral angle of 66.21 (9)°.

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