The title ligand (L”x), methyl 2-((4-cyanophenyl)(hydroxy)methyl)acrylate was synthesized following the Morita-Baylis-Hillman reaction scheme. Spectroscopic techniques such as: UV- Visible, FT-IR, ESI-MS, and 1H NMR helped in characterization of the L”x. Complexes of Cr3+, Co3+, Ni2+, Mn2+, Cu2+ with L”x were prepared and characterized by UV- Visible, FT-IR and powder-XRD. FTIR spectrum of the L”x generated through DFT B3LYP method and 6-311++ G (d,p) basis set was found in good agreement with experimental spectrum. Additionally, the semi-empirical PM6 method optimization helped propose the most suitable geometries of the complexes with Cr3+, Co3+ possessing octahedral, Ni2+ square planner, Mn2+ and Cu2+ tetrahedral geometries. Powder-XRD patterns of the complexes have revealed cubic crystal class for Cr3+ and Co3+, whereas hexagonal, orthorhombic, and monoclinic for Ni2+, Mn2+, and Cu2+ complexes were observed, respectively. In addition, the nano-particle size was found in the range of 8.2560–4.5316 nm for complexes. Antibacterial activity against S. aureus, E. coli, B. pumilis and S. typhi confirmed a substantially high potential, as endorsed by their Molecular docking studies, of Ni2+ and Cu2+ complexes against each bacterial strain. Moreover, all compounds exhibited positive antioxidant activities, but have no antifungal potential except L”x. The current study demonstrates the usefulness of these novel transition metal complexes as possible potent antibacterial and antioxidant agents.

This article reports the synthesis, characterization, geometrical optimization, and biological studies of new MBH-based organometallic compounds of medicinal significance. The ligand (MNHA) was prepared via the Morita–Baylis–Hillman (MBH) synthetic route, from aromatic aldehyde containing multiple functional groups. Metal complexes were prepared in an alkaline medium and under other suitable reaction conditions. Spectral and elemental analyses were used to identify the structural and molecular formulas of each compound. Optimized geometry was determined through density functional theory (DFT) B3LYP and 6-311++ G (d,p) basis set for the MBH adduct, whereas structures of novel complexes were optimized with the semi-empirical PM6 method. Powder XRD analysis furnished the crystal class of complexes, with Co3+, Cr3+, and Mn2+ being cubic, while Ni2+ was hexagonal, and Cu2+ was orthorhombic. Moreover, the ligand, along with Ni2+ and Co3+ complexes, showed profound antibacterial action against S. aureus, E. coli, B. pumilis, and S. typhi. Additionally, all of the complexes were shown to persist in the positive antioxidant potential of the ligand. Contrarily, not a single metal complex conserved the antifungal potentials of the ligand.