Synthesis, crystal structure, Hirshfeld analysis and computational studies of a novel cadmium(II) complex derived from 2-benzoylpyridine-N4-ethyl thiosemicarbazone

A novel sulfur-bridged box dimer cadmium complex, [Cd2(bzpyetsc)2(Cl)2], of 2-benzoylpyridine-N4-ethyl thiosemicarbazone [Hbzpyetsc] ligand prepared and characterized by various physicochemical methods, single crystal X-ray diffraction studies and spectroscopic methods. Single crystal X-ray diffraction studies showed that the prepared complex has a distorted square pyramid coordination around cadmium(II) and the compound crystallized in the monoclinic space group C2/c. The intermolecular hydrogen bonding and weak interaction provide a 2-dimensional laminar structure for the complex. The infrared spectra of the complex revealed that the thiosemicarbazone ligand coordinates to the metal center in its deprotonated thiolate form through the pyridine nitrogen, azomethine nitrogen and thione sulfur atoms. The electronic spectral data showed that the bands assigned to the azomethine bond in the ligand are slightly shifted upon complexation. Furthermore, the complex was optimized and evaluated computationally using the density functional theorem. The HOMO-LUMO analysis revealed that the energy gap is 1.876 eV. Theoretical investigations of the prepared complex are performed by Frontier molecular orbital and molecular electrostatic potential analysis to understand the electron distribution. From the MEP study, it was found that the electron density is predominantly localized around chlorine atoms. Hirshfeld analysis proved that the H-H interaction is the most notable intermolecular interaction.