Syntheses and structural characterization of divalent metal complexes (Co, Ni, Pd and Zn) of sterically hindered thiourea ligand and a theoretical insight of their interaction with SARS-CoV-2 enzyme.

Reacting two equivalents of sterically hindered 1,3-bis(2,6-diethylphenyl)thiourea ligand (L) with CoCl, NiBr, PdX (X = Cl; Br) and ZnI in acetonitrile afforded the corresponding bulky thiourea ligand stabilized four coordinated monomeric [LCoCl] (), [LNiBr] (), [LPdX] (: X = Cl; : X = Br) and [LZnI] () complexes. Compound and are tetrahedral whereas Pd complexes ( and ) are square planar. In solution, palladium complexes are dominated by -isomers. Structural characterization shows inter- and intramolecular hydrogen bonding. Hirshfeld surface and fingerprint plots indicated significant intermolecular interactions in the crystal network. Molecular docking analysis revealed relatively higher SARS-CoV-2 enzyme interacting abilities of the synthesized complexes compared to the free ligand. All compounds have been characterized by elemental analyses, NMR spectroscopy and single-crystal X-ray diffraction.