Potassium N,4-dichlorobenzenesulfonamidate monohydrate

The structure of the title salt hydrate, K+·C6H4Cl2NO2S−·H2O, shows each of the sulfonyl O and water O atoms to be bidentate bridging. The heptacoordinated K+ cation is connected to two water O atoms, four sulfonyl O atoms and one Cl atom. The crystal structure comprises sheets in the bc plane which are further stabilized by O—H⋯N hydrogen bonds.

The structure of the title salt hydrate, K + ÁC 6 H 4 Cl 2 NO 2 S À ÁH 2 O, shows each of the sulfonyl O and water O atoms to be bidentate bridging. The heptacoordinated K + cation is connected to two water O atoms, four sulfonyl O atoms and one Cl atom. The crystal structure comprises sheets in the bc plane which are further stabilized by O-HÁ Á ÁN hydrogen bonds.

Comment
The chemistry of arylsulfonamides and their N-halo compounds is of interest in synthetic, mechanistic, analytical and biological chemistry (Gowda & Shetty, 2004;Usha & Gowda, 2006). To explore the effect of replacing the sodium ion by potassium ion on the solid state structures of N-chloroarylsulfonamides (Gowda et al., 2007a,b), in the present work, the structure of potassium N-chloro-4-chloro-benzenesulfonamidate monohydrate (I) has been determined ( Fig. 1). The structure of (I) resembles those of sodium N-chloro-benzenesulfonamide (George et al., 2000) and other sodium N-chloro-arylsulfonamides (Olmstead & Power, 1986;Gowda et al., 2007a,b). In particular, there is no interaction between the nitrogen and potassium atom in the molecule. K + hepta coordination involves two O atoms from bridging water molecules, four sulfonyl O1 atoms from bridging N-chloro-4-chlorobenzenesulfonamide anions, and one Cl atom (Table 1). This is in contrast to octahedral coordination of K + in potassium N-chloro-benzenesulfonamidate monohydrate by two O atoms from water molecules and four sulfonyl O atoms of four different N-chlorobenzenesulfonamide anions (Gowda et al., 2007a), and octahedral coordination of Na + in sodium N-chloro-4-chlorobenzenesulfonamidate sesquihydrate by three O atoms of water molecules and three sulfonyl O atoms of three different N-chloro-4-chlorobenzenesulfonamide anions (Gowda et al., 2007b). The S-N distance of N1-S1, 1.588 (2) Å is consistent with a S-N double bond.
The crystal structure comprises sheets in the bc plane which are further stabilized by O-H···N hydrogen bonds (Table   2 and Fig. 2).

Experimental
The title compound was prepared according to the literature method (Jyothi & Gowda, 2004). The purity of the compound was checked by determining its melting point. Yellow prisms of (I) were obtained from its aqueous solution at room temperature.

Refinement
The O bound H atoms were located in difference map and later restrained to O-H = 0.82 (2) Å. The other H atoms were positioned with idealized geometry using a riding model with C-H = 0.93 Å. All H atoms were refined with isotropic displacement parameters set to 1.2U eq of the parent atom. 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.