Crystal Structure, Spectroscopic and Thermal Properties of 2-(toluene-4-sulfonylamino)-benzoic Acid

The structure of 2-(toluene-4-sulfonylamino)-benzoic acid (I) derived from X-ray diffraction of a single crystal was presented and verified by using FT-IR, NMR, and elemental analyses. The compound was crystallized in the monoclinic space group C2/c. The lattice parameters are, a=2.7320(3) nm, b=0.85441(8) nm, c=1.17607(11) nm, α=90°, β=98.728(3)°, γ=90°, V=2.7135(5) nm3, and Z=8. The unimolecules in compound I are engaged in N-H⋯O and O-H⋯O hydrogen bonds leading to centrosymmetric dimers, which are interlocked through two distinctly different types of C-H···O hydrogen bonds and face-to-face π···π interactions resulting in an intriguing supramolecular structure. The compound I exhibited solvatochromism as evidenced from UV-Vis study in different solvent media. Moreover, fluorescence spectra and thermal analysis (DSC-TGA) indicated that the compound I was a photochromic and heatproof material.