The work here focusing on the synthesize of a novel (E)-N'-(thiophen-2-ylmethylene)-isonicotinohydrazide as polydentate O-N-S-tridentate Schiff base ligand derived from isonicotinohydrazide and their complexation with CuCl 2 center. The structure of O-N-S-ligand was determined by XRD-crystal diffraction and characterized by IR, UV–Vis., CHN-EA, EDX, 1 H and 13 C-NMR spectroscopy. The DFT/NMR, IR, UV–Vis and optimized structure parameters of the free ligand were matched with their corresponding exp. spectral. The XRD-packing intermolecular has been correlated with the computed Hirshfeld surface analysis (HSA) and MEP-calculation. The Mulliken population and NPA charge analysis, HOMO/LUMO, DOS and global reactivity descriptor quantum parameters (GRD) of the (E)-N'-(thiophen-2-ylmethylene)isonicotinohydrazide ligand were also computed under B3LYP/6-311G(d) theory. The coordination of the ligand to Cu(II) centered were monitored by EDX, FT-IR and UV–Visible analysis. The thermal stability of free ligand and its Cu(II)-complex were evaluated by TG-analysis. © 2019 Elsevier B.V.