Nickel(II) Complexes with Mixed Ligands: Synthesis, WORM Memory Applications, and Potential Biological Applications as Anticancer and Antifungal Agents

Six novel nickel(II) complexes were synthesized using Nickel(II) nitrate hexahydrate, ortho-phenanthroline (o-phen), or 2,2ʹ-bipyridine (bipy) and 1-cyano-1-carboethoxyethylene-2,2-dithiolate (CED2-) ligands through various stoichiometric ratios, showing good solubility across organic solvents. Weight loss experiments suggested water of crystallization, and molar conductance studies indicated electrolytic behavior for some complexes. UV-visible absorption spectra confirmed octahedral coordination around Ni(II), and fluorescence studies showed excitation-dependent emissions. IR confirmed structural details, and current-voltage (I-V) measurements demonstrated resistive switching behavior in memory devices, with compounds exhibiting write-once-read-many (WORM) characteristics. Cytotoxicity studies showed noteworthy activity against the A-549 lung cancer cell line, especially for compounds 1, 4, and 6. Antifungal assays revealed notable activity against certain fungi, enhanced by the metal-ligand interaction increasing lipophilicity. These findings highlight the potential of the complexes in memory devices, anticancer treatments, and antifungal applications.