Abstract

We report the synthesis, structural elucidation, and bioactivity assessment of a novel series of isostructural coordination complexes, M-PBT, with the general formula [M(PBT)2(hfac)2] (M = Mn, Fe, Co, Ni, Cu, Zn), incorporating 2-(pyridin-4-yl)-1,3-benzothiazole (PBT) and hexafluoroacetylacetonate (hfac-) ligands. Single-crystal X-ray diffraction reveals that all complexes crystallize in the triclinic P-1 space group, featuring a trans-octahedral MN2O4 coordination geometry, where PBT ligands occupy axial positions and hfac-ligands coordinate in the equatorial plane. Comparative structural analysis highlights systematic trends in bond lengths and octahedral distortion parameters across the 3d metal series. Hirshfeld surface analysis and 2D fingerprint plots underscore the key role of directional supramolecular interactions, namely C-H & sdot;& sdot;& sdot;F non-classical hydrogen bonds, F & sdot;& sdot;& sdot;F contacts, and it-it stacking, in stabilizing the three-dimensional crystal packing. Theoretical studies corroborate structural findings. Biological assays using Arabidopsis thaliana and Pseudomonas syringae reveal metal-dependent inhibitory effects on plant growth and bacterial proliferation. These results demonstrate that rational selection of metal centers and ligand frameworks can modulate the physicochemical and bioactive properties of coordination complexes, with broader implications for supramolecular design and bioinorganic chemistry.