N,N′-(Ethane-1,2-diyl)bis(4-chlorobenzenesulfonamide)

The title molecule, C14H14Cl2N2O4S2, lies on an inversion center. The molecule is twisted in the region of the sulfonamide group with a C—S—N—C torsion angle of −67.49 (16)°. In the crystal, molecules are connected via intermolecular N—H⋯O and weak C—H⋯O hydrogen bonds, forming layers parallel to (100).

The title molecule, C 14 H 14 Cl 2 N 2 O 4 S 2 , lies on an inversion center. The molecule is twisted in the region of the sulfonamide group with a C-S-N-C torsion angle of À67.49 (16) . In the crystal, molecules are connected via intermolecular N-HÁ Á ÁO and weak C-HÁ Á ÁO hydrogen bonds, forming layers parallel to (100).

Comment
The chemistry of sulfonamides is of interest as they show distinct physical, chemical and biological properties. Many arylsulfonamides and their N-halo compounds exhibit pharmacological, fungicidal and herbicidal activities due to their oxidizing action in aqueous, partial aqueous and non-aqueous media. 2-chlorobenzenesulfonamide has been used to explore the substituent effects on the solid state structures of sulfonamides and N-haloarylsulfonamides (Gowda et al., 2003(Gowda et al., , 2007. The crystal structures of 4-aminobenzenesulfonamide (O'Connor & Maslen, 1965) and 4-methylbenzenesulfonamide (Kumar et al., 1992) have been reported in the literature. In this paper, we present the X-ray single-crystal structure of N,N'-(ethane-1,2-diyl)bis(4-chlorobenzenesulfonamide) (I).

Experimental
In a round bottom flask, 25ml of toluene was mixed with 4-chlorobenzenesulfonyl chloride (0.02 mol, 3.5 g) with stirring.
Drops of ethylenediamine (0.01mol, 0.5 g ) were added and the mixture was refluxed for 30 min. The yellow gum formed was dissolved in hot water and sodium bicarbonate was added. The yellow precipitate formed was dissolved in methanol at 333K, yielding colourless crystals.

Special details
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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.