Methyl 4-chloro-3,5-dinitrobenzoate

In the molecule of the title compound, C8H5ClN2O6, the two nitro groups and the ester group make dihedral angles of 29.6 (1)°, 82.3 (1)° and 13.7 (1)°, respectively, with the benzene ring. In the crystal structure weak C—H⋯O interactions are present.

In the molecule of the title compound, C 8 H 5 ClN 2 O 6 , the two nitro groups and the ester group make dihedral angles of 29.6 (1) , 82.3 (1) and 13.7 (1) , respectively, with the benzene ring. In the crystal structure weak C-HÁ Á ÁO interactions are present.

Related literature
For the use of the title compound as a herbicide, see: Akira et al. (1978); Ferenc et al. (1984).

Experimental
Crystal data

S2. Experimental
A sample of commercial methyl 4-chloro-3,5-dinitrobenzoate (Aldrich) was crystalized by slow evaporation of a solution in methanol: colourless chunk-shaped crystals were formed after several days.

S3. Refinement
H atoms are positioned geometrically, with C-H = 0.95 and 0.98 Å for benzene and methyl H atoms respectively, and are allowed to ride on the C atoms to which they are bonded, with U iso (H) = 1.5U eq (C) for methyl H atoms and U iso (H) = 1.2U eq (C) fot the aromatic H atoms.  A view of the title compound with the atomic numbering scheme. Displacement ellipsoids were drawn at the 30% probability level. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.85 e Å −3 Δρ min = −0.32 e Å −3

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