6-Amino-1,3-dimethyl-5-[(E)-2-(methylsulfanyl)benzylideneamino]pyrimidine-2,4(1H,3H)-dione–1,3,7,9-tetramethylpyrimido[5,4-g]pteridine-2,4,6,8-tetrone (1/1)

Abstract

In the title co-crystal, C12H12N6O4·C14H16N4O2S, both molecules are essentially planar [maximum deviations = 0.129 (1) and 0.097 (1) Å, respectively]. The tricyclic and Schiff base molecules are alternately stacked along theaaxis and are linked by π–π interactions with centroid–centroid distances of 3.5170 (16) and 3.6576 (17) Å. An intramolecular C—H...O hydrogen bond and a C—H...S contact occur in the Schiff base molecule. In the crystal, N—H...O, N—H...N and C—H...O hydrogen bonds lead to the formation of a three-dimensional network.