2-Amino-4-methoxy-6-methylpyrimidin-1-ium picrate

• Main Authors: Jerry P. Jasinski, Ray J. Butcher, H. S. Yathirajan, B. Narayana, K. Prakash Kamath
• Format: Article
• Language: English
• Published: International Union of Crystallography 2010-05-01
• Series: Acta Crystallographica Section E
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S1600536810014583

In the title salt, C6H10N3O+·C6H2N3O7−, the dihedral angle between the mean planes of the benzene and pyridine rings is 3.1 (1)°. In the cation, the methoxy group is almost coplanar with the pyridine ring [C—O—C—N = −0.6 (2)°]. The p-nitro [C—C—N—O = −1.17 (19)°] and one o-nitro [C—C—N—O = 1.83 (19)°] group in the anion are essentially coplanar with the benzene ring. The other disordered o-nitro group containing the major occupancy [0.868 (6)] O atom is twisted −29.0 (2)° from the mean plane of the benzene ring. A bifurcated N—H...(O.O) hydrogen bond and weak C—H...O intermolecular interaction between the cation and anion produce a network of infinite O—H...O—H...O—H chains along the c axis in the [101] plane which helps to establish crystal packing. Comparison to a DFT computational calculation indicates that significant conformational changes occur in the free state.