Thermal, optical, etching, structural studies and theoretical calculations of [1-(2, 5-Dichloro-benzenesulfonyl)-piperidin-4-yl]-(2,4-difluoro-phenyl)-methanone oxime

Abstract

The title compound [1-(2,5-Dichloro-benzenesulfonyl)-piperidin-4-yl]-(2,4-difluoro-phenyl)-methanoneoxime was synthesized by the substitution reaction of 2,4-difluorophenyl(piperidin-4-yl)methanone oxime with 2,5-Dichloro-benzenesulfonylchloride. The synthesized compounds were characterized by different spectroscopic techniques. The structure of the compound was confirmed by single crystal X-ray diffraction studies, which revealed that the piperidine ring adopts a chair conformation. The geometry around the S atom is distorted tetrahedral. The structure exhibits both inter and intra molecular hydrogen bonds of the type O—H···O and C—H···O. The crystal structure is also stabilized by C—Cl···π and π···π interactions. Further, the intermolecular interactions are quantified by Hirshfeld surface analysis. The three dimensional energy framework analysis was carried out and the interaction energies between the molecules were computed. The density functional theory calculation was employed to optimize the structural coordinates and the results substantiate the experimental findings. The HOMO-LUMO energy gap and other electronic parameters of the molecule were evaluated. Further, the reactive sites on the molecular surface were identified using molecular electrostatic potential map. Finally, the thermal properties of the crystals were studied using thermogravimetric analysis which revealed that the structure was stable in the temperature range of 20-170°C.