4-Methyl-3-nitrobenzaldehyde

In the crystal structure of the title compound, C8H7NO3, molecules are linked through weak intermolecular C—H⋯O hydrogen bonding.

In the crystal structure of the title compound, C 8 H 7 NO 3 , molecules are linked through weak intermolecular C-HÁ Á ÁO hydrogen bonding.

Comment
The title compound is an important intermediate for preparing supramolecular electron transfer materials (Yagi et al., 2003;Ezoe et al., 2006) and it has been utilized to synthesize medicinal compounds with biological activities. Herein we report the crystal structure of the title compound (Fig. 1).
The title compound crystallizes in the monoclinic space group P2 1 /c, the unit cell is consists of four molecules. In the title compound, the bond distances and bond angles are similar to those of the reported compound (Zhang et al., 2009). The crystal packing (Fig. 2) is stabilized by a weak intermolecular C-H···O hydrogen bond between the benzene H atom and the oxygen of the aldehyde group (Table 1).

Experimental
The title compound was obtained according to the literature method (Johnson et al., 1991). Single crystals suitable for X-ray diffraction were prepared by slow evaporation of a solution of the title compound in diethyl ether at room temperature.

Refinement
The H atoms were placed in calculated positions, with C-H = 0.93-0.96 Å and refined as riding modrl, with U iso (H) = 1.2-1.5 times U eq (C). Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as a small spheres of arbitrary radius.  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.