Structural studies of the diuretic compound 4-Chloro Salicylic Acid-5-Sulfonamide

Abstract Four polymorphs of the diuretic compound 4-Chloro Salicylic Acid-5-Sulfonamide were obtained by polymorph screening and the crystal structures were determined using X-ray single crystal diffraction technique. The polymorphs were also studied by XRPD, FTIR and the thermal behaviour was investigated by DSC analysis. The supramolecular self assemblies are held by a combination of O–H⋯O, C–H⋯O and N–H⋯O hydrogen bonds, intramolecular hydroxyl-carbonyl O–H⋯O hydrogen bonds being present in all structures. By the use of strong mutual carboxyl-carboxyl O–H⋯O hydrogen bonds, three of the polymorphs are forming centrosymmetric dimers which contain R22(8) motifs. The total lattice energy, which can be partitioned in Coulombic, polarization, dispersion and repulsion components have been computed using the atom-atom Coulomb-London-Pauli forcefield approximation (AA-CLP). Hirshfeld surfaces analysis was employed in order to reveal supplementary details with regard to the intermolecular interactions.