Synthesis, physicochemical characterization, geometric structure and molecular docking of new biologically active ferrocene based Schiff base ligand with transition metal ions

Physicochemical studies were performed to study new ferrocene based Schiff base ligand (HL),(Z)‐(4‐(1‐((2‐carboxycyclohexa‐2,4‐dien‐1‐yl)imino)ethyl)[bis(η5cyclopenta‐1,3‐dien‐1 yl)]ironwith some transition metal ions to form a series of ferrocenyl derivatives bearing transition metal complexes of the type [M(L)Cl(H2O)3] (M = Ni(II), Cu(II)), [M(L)Cl(H2O)3]nH2O (M = Mn(II) (n = 1), Co(II) (n = 1), Zn(II) (n = 2) and Cd(II) (n = 3)) and [M(L)Cl(H2O)3]Cl.nH2O (M = Cr(III) (n = 2) and Fe(III) (n = 1)). The new ligand and metal ion complexes have been prepared and characterized by IR, UV‐Vis,1H‐NMR, TG/DTA, elemental analysis and mass spectrometry. The TGA/DTG analysis revealed that the ferrocene precursors decompose spontaneously to form iron(II) oxide. The molecular and electronic structure of the ligand (HL) was optimized theoretically and the quantum chemical parameters were calculated. The molecular structure with a variety of functionalities can be used to investigate the coordination sites and the total charge density around each atom. DFT‐based molecular orbital energy calculations of the new ligand have been also studied. All of the complexes were screened against a panel of Gram (+) bacteria:Streptococcus pneumoniaeandBacillis subtilis, Gram (−) bacteria:Pseudomonas aeruginosaandEscherichia coliand panel of fungi:Aspergillus fumigatu,Syncephalastrum racemosum,Geotricum candidumandCandida albicans. Anticancer activity screening for the tested compounds using 4 different concentrations of HL ligand against human tumor cells of breast cancer cell line MCF‐7 were obtained. Molecular docking was used to predict the binding between HL ligand and human‐DNA‐Topo I complex (PDB ID: 1SC7), the receptors of breast cancer mutant oxidoreductase (PDB ID: 3HB5), crystal structure ofEscherichia coli(PDB ID: 3T88), to identify the binding mode and the crucial functional groups interacting with the three proteins.