Synthesis, molecular modeling, and docking studies of a new pyridazinone-acid hydrazone ligand, and its nano metal complexes. Spectroscopy, thermal analysis, electrical properties, DNA cleavage, antitumor, and antimicrobial activities

•New nano Co(II), Ni(II), Cu(II), Zn(II), Fe(III) complexes, and oxovanadium(IV), dioxouranium(VI) complexes of pyridazinone-acid hydrazone ligand have been synthesized and characterized.•The antimicrobial and antitumor evaluations showed enhancement in activity of the free ligand upon complexation.•Molecular modeling studies indicated that the theoretical data agree well with the experimental results.•The docking results suggesting strong interactions of both the ligand and its Cu(II) complex with the VEGFR-2 enzyme.•The ligand and its nano Cu(II) complex behave as semiconductors. New nano Co(II), Ni(II), Cu(II), Zn(II), Fe(III) complexes, and oxovanadium(IV), dioxouranium(VI) complexes of pyridazinone-acid hydrazone ligand, DCNHP (H2L), in addition of new mixed-ligand complexes using 8-HQ/or 1,10-phen as an auxiliary ligand (L\), have been synthesized and characterized by different techniques. The ligand, H2L, acted as tridentate towards the metal ions in a mono-, and bis- deprotonated form. The complexes exhibited a variety of geometrical structures including octahedral, square pyramidal, and tetrahedral configurations. The results of TGA confirmed the thermal stability of the metal complexes. The X-ray diffractograms and TEM images confirmed that the particles of the investigated compounds have been situated in nano-range with spherical and stick-shaped. Molecular modeling studies indicated that the theoretical data agree well with the experimental results. The antimicrobial activity study showed enhancement in activity of the free ligand upon complexation. The results of antitumor screening indicated that all examined compounds displayed inhibition of Hepatocellular carcinoma cell line (HepG-2) viability. The ligand, H2L, and its nano Cu(II) complex 7 displayed strong antitumor activity with IC50 = 3.80 and 3.81 μg/mL, respectively. The DNA cleavage study revealed that no ability for the screened compounds to cleavage DNA, and they may be able to induce cellular death in cancer cells through the apoptosis pathway. The docking results suggesting strong interactions of both the ligand, H2L, and its Cu(II) complex 7 with the VEGFR-2 enzyme, these interactions are very similar to that of the known hepatocellular carcinoma (HCC) inhibitor, sorafenib (Nexavar) with the target enzyme, and indicating the effective inhibition of the investigated compounds towards hepatocellular carcinoma. Moreover, the electrical conductivity study in solid-state revealed that