2,4-Dinitro-1-naphthyl 4-toluenesulfonate

In the title compound, C17H12N2O7S, the dihedral angle between the benzene ring and the naphthyl plane is 26.34 (6)°. The nitro groups make dihedral angles of 40.09 (4) and 37.05 (3)° with the naphthyl plane. In the crystal structure, weak intra- and intermolecular C—H⋯O interactions are observed.

In the title compound, C 17 H 12 N 2 O 7 S, the dihedral angle between the benzene ring and the naphthyl plane is 26.34 (6) . The nitro groups make dihedral angles of 40.09 (4) and 37.05 (3) with the naphthyl plane. In the crystal structure, weak intra-and intermolecular C-HÁ Á ÁO interactions are observed.
In addition to this, because of the presence of highly electron attracting nitro groups, there are strong dipole-dipole attractions between different molecules in the lattice arrangement. The nitro group substituted naphthylring, which is electron deficient is found to be lying over the electron rich tolyl benzene ring of another molecule in the lattice. This leads to a sort of charge transfer complex.
The enhanced stability of this compound and larger stability of the lattice when compared to other sulfonates reported already, is supported by thermoanalytic studies. This compound is having higher density, melting point and higher lattice energy when compared to others. Another interesting property of this compound is that it possesses antibacterial activity almost equivalent to those of antibiotics. This is attributed to the elongation of the S-O (S1-O3) bond in -S-O-naphthyl ring such that the dissociation to naphthoxy moiety is facilitated. The facile formation of the naphthoxy radical is further supported by the high intensity peak for this specy in the Mass spectra. Kinetic studies also indicate that the rate of hydrolysis (rate of cleavage of the -S-O-bond) is very high when compared to other toluene sulfonates reported already.
The molecular structure is stabilized by weak intramolecular C-H···O interactions and the crystal packing of (I) (Fig. 2) is stabilized by weak intermolecular C-H···O interactions.

Experimental
Calculated quantity of (10 mmol) of alpha naphthol was dissolved in hot con. sulfuric acid (10 ml) and heated for 10 minutes over a water bath to get disulfonic acid. To this was added (10 ml) of fuming nitric acid in small quantity at a time with stirring. After the addition was over the reaction mixture was kept aside for an hour. It was poured into crushed ice with stirring. The precipitate was filtered, washed with cold water, dried and recrystallized from rectified spirit.
A solution of the above 2,4-dinitronaphthol and triethylamine in acetone was treated with sulfonyl chloride in acetone.
This was left as such overnight. The solvent was evaporated and the residue was washed with triethylamine solution. The crude product was recrystallized from ethanol to get diffraction quality crystal of 2,4-dintro-1-naphthyl-4-toluene sulfonate.
supplementary materials sup-2 Refinement H atoms were positioned geometrically and refined using riding model with C-H = 0.93 Å and U iso (H) = 1.2U eq (C) for aromatic C-H, and with C-H = 0.96 Å and U iso (H) = 1.5U eq (C) for CH 3 . Fig. 1. The molecular structure of (I), with atom labels and 50% probability displacement ellipsoids for non-H atoms.