Synthesis, characterization, biological activity, DFT and Hirshfeld surface studies of Pd(II) and Pt(II)-1-cyclohexyl-3-phenylthiourea and amine ligands

A series of mixed ligand complexes of Pd(II) and Pt(II) of 1-cyclohexyl-3-phenylthiourea and diamine ligands {2,2'-bipyridyl (Bipy) and 1,10-phenanthroline (Phen)} were prepared and characterized by FT-IR, NMR spectroscopy, molar conductivity. Density functional theory (DFT) calculations and biological activity were carried out on the prepared complexes. In vitro antimicrobial activity was investigated against three pathogenic bacteria (Staphylococcus aureus, Bacillus cereus and Escherichia coli). The most active compound 6 was found more active than free ligand and other complexes. The crystal structure of the free ligand was determined by X-ray diffraction (XRD) analysis. Hirshfeld surface analysis was executed for the free ligand by finding and exploring the interatomic contacts that are important considering the supramolecular assembly of the crystal. The mechanical stability or response is prophesied by voids analysis. The supramolecular assembly is significantly uncovered by intermolecular interaction energies calculations performed at of the B3LYP/6-31G(d,p) electron density level. KEY WORDS: Thiourea, Diamine, Crystal structure, DFT, Hirshfeld surface Bull. Chem. Soc. Ethiop. 2025, 39(1), 15-27. DOI: https://dx.doi.org/10.4314/bcse.v39i1.2