1-(2,6-Dichloro-benzo-yl)-3-(3-nitro-phen-yl)thio-urea dimethyl-formamide solvate.

In the title compound, C(14)H(9)Cl(2)N(3)O(3)S·C(3)H(7)NO, the two aromatic rings enclose a dihedral angle of 32.93 (12)°. The thiourea mol-ecule exists in its thione form in the solid state with typical C=S and C-N bond lengths. In the crystal, N-H⋯O hydrogen bonds exist between the thio-urea and carbonyl groups on the same and neighboring mol-ecules. In addition, each dimethyl-formamide solvate mol-ecule forms a hydrogen bond to one N atom of the thio-urea group.

In the title compound, C 14 H 9 Cl 2 N 3 O 3 SÁC 3 H 7 NO, the two aromatic rings enclose a dihedral angle of 32.93 (12) . The thiourea molecule exists in its thione form in the solid state with typical C S and C-N bond lengths. In the crystal, N-HÁ Á ÁO hydrogen bonds exist between the thiourea and carbonyl groups on the same and neighboring molecules. In addition, each dimethylformamide solvate molecule forms a hydrogen bond to one N atom of the thiourea group.

Comment
Earlier studies have shown that thiourea and urea derivatives have played an important role in developing agrochemicals and pharmacological agents (Dowding & Leeds, 1971;Sasse et al., 1969;Darlington et al., 1996). As part of our interest in N,N'-disubstituted thioureas, we now report the crystal structure of the title compound (I).
The N-C bonds in (I), see Fig. 1, differ significantly from one another but are short in comparison with the typical value for an N-C single bond (1.479 Å). Owing to the introduction of the C=O electron-acceptor group the adjacent C-S bond length [1.652 (2)Å ] is shorter than previously reported C=S distances (1.710 (7)Å) (Bailey, et al., 1997). These distances are similar to those usually found in other substituted thioureas (Khawar Rauf et al., 2006a, 2006b, 2006c, 2007, 2009. The dihedral angle between the aromatic rings is 32.93 (12)°, and the corresponding angles with the thiourea plane are 83.52 (7)° for the C2-C7 ring and 50.61 (7)° for the C9-C14 ring.The thiocarbonyl and carbonyl groups are almost coplanar.
Inter-and intramolecular N-H···O hydrogen bonds exist between the thiourea N-H-atoms and carbonyl-O atoms. In addition, each dimethylformamide solvate molecule also has a hydrogen bond to the N of the thiourea groups (2.787 (3) Å: Table 1, Fig. 2).

Experimental
Freshly prepared 2,6-dichlorobenzoylisothiocyanate (2.32 g, 10 mmol) was added to dimethylformamide (30 ml) and stirred for 2 minutes. Afterwards neat 3-nitroaniline (1.38 g, 10 mmol) was added and the resulting mixture was stirred for 1 h.The reaction mixture was then poured into an ice-water mixture and stirred well. The solid product was separated and washed with deionized water and purified by recrystallization from methanol/CH 2 Cl 2 (1:1 v/v) to give fine crystals of the title compound (I), with an overall yield of 85%.

Refinement
All H atoms were positioned geometrically, with C-H = 0.96-0.98 Å, and refined as riding, allowing for free rotation of the methyl groups. The U iso (H) values were set at 1.5U eq (C).  as those based on F, and R-factors based on ALL data will be even larger.