2,5-Dibenzoylbenzene-1,4-diaminium dichloride

The asymmetric unit of the title compound, C20H18N2O2 2+·2Cl−, is composed of one-half of the 2,5-dibenzoylbenzene-1,4-diaminium dication, located on a centre of inversion, and one Cl− ion. The dihedral angle between the central benzene ring and the benzoyl phenyl ring is 53.3 (2)°. In the crystal structure, ions are linked to form a two-dimensional network parallel to the (10) plane by N—H⋯Cl hydrogen bonds.

The asymmetric unit of the title compound, C 20 H 18 N 2 O 2 2+ Á-2Cl À , is composed of one-half of the 2,5-dibenzoylbenzene-1,4-diaminium dication, located on a centre of inversion, and one Cl À ion. The dihedral angle between the central benzene ring and the benzoyl phenyl ring is 53.3 (2) . In the crystal structure, ions are linked to form a two-dimensional network parallel to the (101) plane by N-HÁ Á ÁCl hydrogen bonds.

Experimental
Crystal data
In the crystal structure, molecules are connected together by N-H···Cl hydrogen bonds (Table 1) to form a two-dimensional network parallel to the (1 0 1) plane (Fig. 2).
Experimental 2,5-Dibenzoyl-1,4-phenylenediamine was synthesized as reported elsewhere (Imai et al., 1975). Single crystals suitable for X-ray diffraction were obtained by dissolving the compound (2.0 g, 6.3 mmol) in hydrochloric acid (50 ml, 1.0 mol/l) and allowing the solution to evaporate at room temperature for about 25 d.

Refinement
N-bound H atoms were located in a difference map and refined with the N-H distances restrained to be equal. C-bound H atoms were positioned geometrically (C-H = 0.93 Å) and constrained to ride on their parent atoms, with U iso (H) = 1.2U eq (C).  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.