Computational investigation of structural, nonlinear optical and anti-tumor properties of dinuclear metal carbonyls bridged by pyridyl ligands with alkyne unit

Abstract

Dinuclear metal carbonyls bridged by pyridyl ligands with alkyne unit, [(OC)5W]2(μ-DPA) (1), [(OC)5W]2(μ-DPB) (2) and [(OC)5W]2(μ-BPEB) (3), where DPA = 4,4′-dipyridylacetylene, DPB = 4,4′-dipyridylbutadiyne and BPEB = 1,4-bis(4′-pyridylethynyl)benzene, are optimized at B3LYP/(LANL2DZ)(6-31 + G(d)) level. Molecular structures of the complexes are characterized by computational structural parameters, IR, UV–Vis and NMR spectra. According to calculated structural parameters and spectral analysis, the environment geometry of central metal atoms was found to be close to ideal octahedral consistent with C4v symmetry. Non-linear optical (NLO) properties of the complexes are predicted from energy gap (ΔE), static dipole moment (μ), average linear polarizability (α), anisotropy of polarizability (Δα) and first hyperpolarizability (β) values. Since the μ, α and β values of the complexes are lower than that of reference urea, it is estimated that the complexes don't have NLO characteristics. Anti-tumor activities of the complexes are predicted from the highest occupied molecular orbital energy (EHOMO), the lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE), hardness (η), electronegativity (χ), chemical potential (μcp), electrophilicity index (ω) and molecular docking studies. Comparison of the molecular descriptors and molecular docking results of the complexes with cis-platin indicates that all the complexes are the best candidate for anti-tumor drug.