Luminescent properties of heterotrinuclear 3d-4f complexes constructed from a naphthalenediol-based acyclic bis(salamo)-type ligand.

Heterotrinuclear 3d-4f complexes with a naphthalenediol-based acyclic bis(salamo)-type ligand have been synthesized and structurally characterized. Spectral titrations clearly show that the heterotrinuclear complexes [Zn(L)La(OAc)] (1), [Zn(L)Ce(OAc)] (2) and [Zn(L)Dy(OAc)(CHOH)]·CHCl (3) are acquired by the substitution reaction of the obtained homotrinuclear Zn(II) complex with 1 equiv. of Ln(NO) (Ln=La, Ce and Dy). Two Zn(II) ions are penta- and hexa-coordinated with geometries of distorted tetragonal pyramid and octahedron. La(III) ion is deca-coordinated, adopting a distorted bicapped square antiprism geometry. Ce(III) ion is nona-coordinated with geometry of distorted capped square antiprism as well as Dy(III) ion. The different coordination modes of acetate ions in complexes 1, 2 and 3 lead to different coordination numbers of the lanthanide(III) ions. Furthermore, the structures and fluorescence properties have been discussed.