Synthesis, spectral, structural, DFT and NLO studies of cerium(III) and thorium(IV) complexes of 1-(5-(1-(2-aminophenylimino)ethyl)-2,4-dihydroxyphenyl)ethanone

Reactions of cerium(III) and thorium(IV) nitrates with the Schiff base 1-(5-(1-(2-aminophenylimino)ethyl)-2,4-dihydroxyphenyl)ethanone (H2L) gave two neutral mononuclear complexes, [Ce(HL)(NO3)(2)(H2O)]center dot EtOH (1) and [Th(HL)(NO3)(3)(H2O)]center dot 6H(2)O (2), respectively. The complexes were characterized by elemental and thermal analyses, IR, electronic, H-1 NMR and mass spectra, molar conductivity and magnetic susceptibility measurements. Analytical and spectroscopic methods illustrated that the Schiff base acts as a monoanionic tridentate N2O-ligand. This paper shows a correlation between the structure of the cerium(III) and thorium(IV) complexes experimentally and theoretical study on molecular structure, thermo-chemical parameters and the harmonic vibration frequencies of them. The geometrically optimized structures of the complexes are non-planar. HOMO and LUMO gap energy is small, the charge transfer occurring within cerium(III) and thorium(IV) complexes indicates a greater reactivity and conversely, low chemical stability.