Spectral, DFT—TDDFT computational investigation and biological studies of transition metal complexes of dehydroacetic acid schiff base

Abstract

Schiff base of dehydroacetic acid ligand (HL) and its transition metal complexes were prepared. The complexes were described by elemental analyses, molar conductivities, magnetic moments and spectral analyses. From the IR spectra, the ligand (HL) behaves as monobasic di- or tridentate ligand coordinated to the metal ions via azomethine N and O. UV spectra and magnetic moment show that the Cu(II), Co(II) and Ru(III) complexes have octahedral, Fe(III), Mn(II) and Ni(II) complexes have tetrahedral geometry and Pd(II) and Ag(I) complexes show square planar geometry. The complexes [Pd2(HL) Cl4] and [Ru(L)Cl2. 2H2O] 3H2O have antibacterial activities toward all the gram-positive, negative bacteria and fungi. The compounds have antitumor activity arrangement against HEPG2 liver cell [Pd2(HL) Cl4] > [Ru(L)Cl2. 2H2O]. 3H2O > HL and have the following arrangement against MCF7 breast cell HL > [Pd2(HL) Cl4] > [Ru(L)Cl2. 2H2O]. 3H2O. The geometries, bonding characteristics, frontier orbital energy gaps, NBO analysis dipole moments, hyperpolarizabilities, thermochemical properties, PDOS plot and simulated absorption spectra (IR and UV–visible spectra) of the ligand and its Cu (II) and Co(II) complexes have been examined by means of the time-independent density functional theory (B3LYP and CAM-B3LYP) as well as the time-dependent density functional theory (TD-B3LYP and TD-CAM-B3LYP)