1-(2-Methyl-5-nitro-phenyl)guanidinium picrate

Abstract

In the crystal structure of the title salt, C8H 11N4O2+·C6H 2N3O7-, the pictrate anion participates in extensive hydrogen bonding with the guanidinium ion group of the cation, linking the mol-ecules through N+- H⋯O- hydrogen bonds and inter-molecular N- H⋯O and C- H⋯O inter-actions. These hydrogen-bonding configurations involve two three-centre/bifurcated bonds [N- H⋯(O,O)] that are observed between two N atoms from the guanidinium ion group of the cation and the o-NO2 and phenolate O atoms of the picrate anion. In addition, π-π inter-actions also contribute to the crystal packing, with a centroid-to-centroid distance of 3.693 (6) Å and a slippage angle of 1.614°. A significant number of conformational differences are observed between the salt in the crystal structure and the models obtained by density functional theory (DFT) calculations of the geometry-optimized structure.