title: N,N-dimethylanilinium 3-cyano-4-(dicyanomethylene)-5-oxo-4,5-dihydro-1H-pyrrol-2-olate.
abstract: In the title compound, C(8)H(12)N(+).C(8)HN(4)O(2)(-), the anion and cation lie on a crystallographic mirror plane and form planar ribbons via N-H...O [N...O = 2.933 (4) A, H...O = 2.01 A and N-H...O = 170 degrees] and N-H...N [N...N = 3.016 (5) A, H...N = 2.15 A and N-H...N = 169 degrees] hydrogen bonds. The ribbons are further linked via weak C-H...O and C-H...N hydrogen bonds. In adjacent planes, anions lie opposite cations; pi-pi interactions (separation a/2 = 3.520 A) exist between the anions and the cations, and stacks are formed, running along the a axis. The cations are disordered over two interpenetrating sites, with occupancies of 0.833 (5) and 0.167 (5).
authors.affiliation: Chemistry Department, Moscow State University, 119899 Moscow, Russia. tafeenko@biocryst.phys.msu.su
authors.forename: Viktor A
authors.initials: VA
authors.lastname: Tafeenko
authors.forename: Rene
authors.initials: R
authors.lastname: Peschar
authors.forename: Olga V
authors.initials: OV
authors.lastname: Kaukova
authors.forename: Henk
authors.initials: H
authors.lastname: Schenk
authors.forename: Leonid A
authors.initials: LA
authors.lastname: Aslanov