Hydrogen-bonding and pi-pi interactions in 2-amino-4,6-dimethylpyrimidinium salicylate.

In the crystal structure of the title compound, C6H10N3+.C7H5O3-, the asymmetric unit contains four crystallographically independent 2-amino-4,6-dimethylpyrimidinium and salicylate ions (Z = 8). In each of these, one of the pyrimidine N atoms is protonated, and the carboxylate group of the salicylate ion interacts with the pyrimidine group through a pair of N-H...O hydrogen bonds, forming an R2(2)(8) motif. The pyrimidine cations also form base pairs via a pair of N-H...N hydrogen bonds (involving the amino group and the unprotonated ring N atom), forming another R2(2)(8) motif. Three such R2(2)(8) motifs, fused together, constitute a closed cyclic aggregate, and the linking of these aggregates, arranged in consecutive layers, can be analysed in terms of off-face stacking interactions.