Synthesis, crystal structure and NMR investigation of novel Ca(II) complexes with heterocyclic alcohol, aldehyde and carboxylate ligands. Evaluation of Ca(II) and Cd(II) analogues for anticancer activity

► New calcium(II) complexes with chelating N, O-ligands were synthesized. ► Obtained complexes are small models for calcium coordination in biological systems. ► The comparison of X-ray data of Ca(II) and Cd(II) complexes was done. ► From chemical point of view X-ray data confirmed that toxic Cd(II) may replace Ca(II) in biological systems too. ► Cd(II) analogues tested for cytotoxicity revealed similar activity.