Electron Charge Density Distribution from X-Ray Diffraction Study of the 4-Methoxybenzenecarbothioamide Compound

The molecular electron charge density distribution of the title compound is described accurately using the multipolar model of Hansen and Coppens. The net atomic charge and the in-crystal molecular dipole moment have been determined in order to understand the nature of inter- and intramolecular charge transfer. The study reveals the nature of intermolecular interactions including charge transfer and hydrogen bonds in the title compound. In this crystal, the molecules form dimers via N–H S intermolecular hydrogen bonds. The dimers are further linked by C–H O hydrogen bonds into chains along the c crystallographic axis. This study has also allowed us to determine the electrostatic potential and therefore locate the electropositive part and the electronegative part in molecular scale of the title compound. 1. Introduction The chemistry of thioamides and their derivatives continues to be of particular interest due to their interesting structural features and also due to their biological importance. Heterocyclic compounds of these types exhibit a wide spectrum of biological activity and have extensive practical applications [1–3]. In addition, thioamides are important ligands in the field of coordination chemistry [4]. Due to these positive traits, thioamides have been under study for a long time, but much of their basic chemistry remains unexplored. The heterocyclic 4-methoxybenzenecarbothioamide compound, of chemical formula C8H9NOS, crystallizes in the P212121 space group, with eight molecules in the unit cell. The general features of the structure have been described previously [5]. It contains two independent molecules with the methoxy groups oriented in opposite conformations. The mean planes of the carbothioamide groups are tilted by 7.88(15) and 11.16°(9) from the mean planes of the benzene rings. In this work, the crystallographic data were taken from another article [5] and used for the current study. The structure has been redetermined using the same X-ray diffraction data. So this work focuses on the thermal analysis and electronic charge density study of the 4-methoxybenzenecarbothioamide molecule. The scope of this study is to model aspherical features of the atomic electron density arising from chemical bonding at low temperature of the molecule by transferring the electron density multipole parameters obtained from accurate X-ray diffraction experiments and calculate the molecular dipole moment. In order to understand the nature of inter- and intramolecular charge transfer, the electrostatic potential distribution of the molecule in crystal