Benzamidinium 2-meth­oxy­benzoate

The title mol­ecular salt, C(7)H(9)N(2) (+.)C(8)H(7)O(3) (−), 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 R (2) (2)(8). These ionic dimers are then joined in ribbons running along the b-axis direction by another R (4) (2)(8) motif involving the remaining N(+)—H⋯O(−) hydrogen bonds. Remarkably, at variance with the well known carb­oxy­lic dimer R (2) (2)(8) motif, the carboxyl­ate–amidinium pair is not planar, the dihedral angle between the planes defined by the CN(2) (+) and CO(2) (−) atoms being 18.57 (12)°.