Cytosinium orotate dihydrate

Benzamidinium 2-meth-oxy-benzoate

The title mol­ecular salt, C₇H₉N₂^+.C₈H₇O₃⁻, was synthesized by reaction between benzamidine (benzene­carboximidamide) and 2-meth­oxy­benzoic acid. In the cation, the amidinium group has two similar C—N bonds [1.3070 (17) and 1.3145 (16) Å] and is almost coplanar with the benzene ring, making a dihedral angle of 5.34 (12)°. In the anion, the meth­oxy substituent forces the carboxyl­ate group to be twisted by 69.45 (6)° with respect to the plane of the aromatic fragment. In the crystal, the components are connected by two N⁺—H⋯O⁻ (±)CAHB (charge-assisted hydrogen bonds), forming centrosymmetric ionic dimers with graph-set motif R₂²(8). These ionic dimers are then joined in ribbons running along the b-axis direction by another R₄²(8) motif involving the remaining N⁺—H⋯O⁻ hydrogen bonds. Remarkably, at variance with the well known carb­oxy­lic dimer R₂²(8) motif, the carboxyl­ate–amidinium pair is not planar, the dihedral angle between the planes defined by the CN₂⁺ and CO₂⁻ atoms being 18.57 (12)°.