1,3-Diphenylpropan-2-one (2,4-dinitrophenyl)hydrazone

In the title compound, C21H18N4O4, there is an intramolecular N—H⋯O hydrogen bond between the amino H atom and an O atom of the 2-nitro group of the adjacent benzene ring. The central benzene ring forms dihedral angles of 79.98 (7) and 82.88 (7)° with the two phenyl rings. In the crystal structure, molecules are linked into a three-dimensional network by weak C—H⋯N, C—H⋯O and C—H⋯π interactions.

In the title compound, C 21 H 18 N 4 O 4 , there is an intramolecular N-HÁ Á ÁO hydrogen bond between the amino H atom and an O atom of the 2-nitro group of the adjacent benzene ring. The central benzene ring forms dihedral angles of 79.98 (7) and 82.88 (7) with the two phenyl rings. In the crystal structure, molecules are linked into a three-dimensional network by weak C-HÁ Á ÁN, C-HÁ Á ÁO and C-HÁ Á Á interactions.
one(2,4-dinitrophenyl)hydrazone (Lima et al., 2009). In addition to this hydrogen bond there are three weak intermolecular hydrogen bonds and two C-H···π interactions which link the molecules into a three-dimensional network.

Experimental
(1) was obtained from the condensation reaction of dibenzylketone with 2,4-dinitrophenylhydrazine. Orange needles suitable for X-ray diffraction were grown from dichloromethane.

Refinement
Molecule (1) crystallized in the monoclinic system; space group P2 1 /c. H atoms were treated as riding atoms with C-H(aromatic), 0.95 Å, C-H(CH 2 ), 0.99 Å. The atom attached to N1 was located on a difference map at a distance of 0.9123Å and was fixed as a riding atom at this distance. Fig. 1. A view of (1) with our numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An apprO122imate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 Rfactors(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.