Novel amide based macrocyclic complexes of Co(II): Synthesis, structural characterization, thermal, DFT, molecular docking studies, in vitro cytotoxic, antimicrobial and antioxidant evaluation

Abstract

The novel cobalt (II) macrocyclic complexes [Co(N4O4MacL1)Cl2]-[Co(N4O4MacL3)Cl2] have been synthesized by using the macrocyclic ligands [N4O4MacL1], [N4O4MacL2] and [N4O4MacL3] that have an N4O4 core. To investigate Co(II), metal complexes [Co(N4O4MacL1)Cl2]-[Co(N4O4MacL3)Cl2] with new ligands, elemental analyses, infrared, magnetic measurements, UV–visible, 1H NMR, 13C NMR, and XRD studies were utilised. According to the spectrum data, the ligands perform as a mononegative tetradentate. Based on magnetic and electronic spectrum data, an octahedral structure for Co(II) metal complexes has been postulated. The Coats-Redfern and FWO techniques are used to determine the thermodynamic characteristics of ligands and their complexes. The molecular modelling using the DFT technique displays bond angles, bond lengths, and quantum chemical factors. To determine their ability to prevent the growth of harmful fungus and bacteria, the ligands [N4O4MacL1]- [N4O4MacL3] and their complexes were tested in vitro against A. Niger, C. albicans and B. subtilis, S. aureus, E. coli and S. typhi fungal and bacterial organisms, respectively. By using DPPH free radical scavenger assays, the in vitro antioxidant capabilities of each compound were evaluated. The [Co(N4O4MacL3)Cl2] antioxidative capabilities revealed significant radical scavenging power. All of the compounds under research were examined for cytotoxicity using the MTT assay on MCF-7 and HepG-2 cells, and the findings revealed that [Co(N4O4MacL2)Cl2] show outstanding cytotoxic activity against HepG-2 with IC50 17.94 ± 045 at a concentration of 25 ppm. Additionally, docking investigations of the produced compounds were carried out in order to validate the biological outcomes. Considerably, the current Co (II) complexes with their effective antimicrobial, antioxidant, and cytotoxicity activity would be probably appraised for further medicinal and pharmaceutical applications.