Preparation and physico-chemical properties of lanthanide(III) complexes with 2-((E)- (tert- butylimino)methyl)-6-methoxyphenol

Abstract

ABSTRACT. The reactions of lanthanide nitrates with 2-((E)-(tert-butylimino)methyl)-6-methoxyphenol (HL1) have yielded five complexes that are described by the formulae  [Ce(HL1)2(NO3)3]∙MeOH and [Ln(HL1)2(NO3)3] (Ln = Nd(III), Gd(III), Ho(III) and Er(III)) and were characterized using physico-chemical techniques including single-crystal X-ray diffraction spectroscopy. The cerium complex crystallized in a triclinic P-1 space group, while the rest of the complexes crystallized in the monoclinic P21/c space group. All the complexes are ten-coordinate, adopting a tetradecahedron geometry with two HL1 molecules coordinated through the phenolic and methoxy oxygen atoms. The coordination sphere is completed by six oxygen atoms from three bidentately coordinated nitrate ligands. Electronic data reveals that only the neodymium, holmium and erbium complexes exhibit weak f-f transitions in the visible region. KEY WORDS: Preparation, Physico-chemical properties, Lanthanide, Schiff base complexes, Crystal structure, Geometry Bull. Chem. Soc. Ethiop. 2023, 37(6), 1397-1410. DOI: https://dx.doi.org/10.4314/bcse.v37i6.8