1,3-Bis(2-anilino-2-oxoethyl)-1H-imidazol-3-ium chloride dimethylformamide monosolvate

In the imidazolium cation of the title compound, C19H19N4O2 +·Cl−·C3H7NO, the dihedral angles between the imidazole ring and the phenyl rings are 85.86 (4) and 70.26 (5)°. In the crystal, N—H⋯Cl hydrogen bonds link the imdiazolium cations and chloride anions into zigzag chains along [110] and together with C—H⋯Cl and C—H⋯O hydrogen bonds, which involve also the dimethylformamide solvent molecule, form a two-dimensional network extending across the ab plane.

In the imidazolium cation of the title compound, C 19 H 19 N 4 O 2 + ÁCl À ÁC 3 H 7 NO, the dihedral angles between the imidazole ring and the phenyl rings are 85.86 (4) and 70.26 (5) . In the crystal, N-HÁ Á ÁCl hydrogen bonds link the imdiazolium cations and chloride anions into zigzag chains along [110] and together with C-HÁ Á ÁCl and C-HÁ Á ÁO hydrogen bonds, which involve also the dimethylformamide solvent molecule, form a two-dimensional network extending across the ab plane.

Experimental
Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: DIAMOND (Brandenburg, 2006). In the structure of the title compound ( Fig. 1), the dihedral angles between the heterocyclic ring and the two phenyl rings in the imdiaozlium cation.are 85.86 (4)° and 70.26 (5)° and the molecular conformation is stabilized by intramolecular C7-H···O3 and C15-H···O1 interations. In the crystal, classical intermolecular hydrogen bonds of the type N-H···Cl (Table 1) involving both N4 and N5 link the cations into zigzag chains along the [110] direction and together with non-classical C-H···O and C-H···Cl hydrogen bonds further connect these chains and the DMF solvent molecules into two-dimensional layers lying on the ab plane (Fig. 2).

Experimental
The compound was prepared according to the literature procedure (Liao, Chan, Zeng et al., 2007). Suitable crystals were obtained by slow diffusion of diethyl ether into a DMF solution of the compound at room temperature.

Refinement
All of the hydrogen atoms could have been discerned in the difference-Fourier map but were positioned geometrically and refined as riding atoms, with C aryl -H = 0.95, C methyl -H = 0.98, C methylene -H = 0.99, C methine -H = 0.95, and NH = 0.88 Å , with U iso (H) = 1.2U eq (C aryl , C methylene , C methine and N) and U iso (H) = 1.5 U eq (C methyl ).  The structure of the title compound, showing 50% probability displacement ellipsoids for the non-hydrogen atoms. The H atoms are shown as spheres of arbitrary radius.

Figure 2
The crystal packing viewed down the a axis, displaying the hydrogen bonds as dashed lines.  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 > σ(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.