IUCr journals

N,N-Dimethylanilinium 3-cyano-4-(dicyanomethylene)-5-oxo-4,5-dihydro-1H-pyrrol-2-olate

Acta Cryst. (2004). C60, o62–o64 [doi:10.1107/S0108270103025940]

[Anilinium pyrrolate]
On the basis of the structural data and the calculated charge distribution on the atom of the title anion, the following types of the anion–cation interaction can be postulated: a) “isotropic” interaction with each outer heteroatom of the anion taking part in the formation of a polyhedron enclosing the cation (alkali, alkali-earth metals); b) π–π stacking interaction, involving planar cations (e.g. pyridinium); c) transition metal – π-system of the anion interaction (e.g. ferrocene); and d) interaction of the heteroatoms of the anion and transition metals to form a coordination compound, chelate complex or polymeric structure. In the title salt, anions and cations overlap to form π–π stacks along the a axis.

Viktor A. Tafeenko, Rene Peschar, Olga V. Kaukova, Henk Schenk and Leonid A. Aslanov