A novel metallacoronate complex of osmium: Synthesis, spectroscopic analysis, crystal structure, Hirshfeld surface analysis, DFT and anticancer studies

A novel osmium metallacoronate complex 12-MC Os(II)(ox) -6 with an oxalato spacer is reported. The synthesis method and complete characterisation data, including elemental analysis, spectroscopy (IR, Raman, NMR, UV-visible and Fluorescence) and single-crystal X-ray diffraction, are presented. The FTIR and Raman support the proposed coordination mode of the oxalato ligand, while the crystallography data confirm the coordination of the oxalato ligand. Hirshfeld surface analysis exhibits hydrogen bonding as the predominant non-covalent interaction. The frontier molecular orbital analysis indicates that complex 1 is kinetically stable owing to the large HOMO-LUMO gap, which is supported by experimental chemical stability studies in DMSO- d 6 using 1 H NMR. The cytotoxicity of the metallacoronate against the Human epidermoid carcinoma (A431), Hepatocellular carcinoma (HepG2), Human cervical epithelial carcinoma (HeLa) and Breast cancer (MCF-7) cancer cell lines is also reported. The molecular structure shows an inner cavity , defined by the oxalato ligands, with an estimated volume of ca. 39 Å 3 .