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

Abstract

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)]·EtOH (1) and [Th(HL)(NO₃)₃(H₂O)]·6H₂O (2), respectively. The complexes were characterized by elemental and thermal analyses, IR, electronic, ¹H 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.

Graphical Abstract

Keywords:

• Cerium(III) and thorium(IV) complexes
• DFT studies
• 4,6-diacetylresorcinol
• NLO
• Schiff base ligand

Disclosure statement

No potential conflict of interest was reported by the authors.