Syntheses and Crystal and Molecular Structure of [Hexaaquabis(2-naphthalenesulfonato)lanthanoid(III)] 2-Naphthalenesulfonate Trihydrate, [Ln(C10H7SO3)2(H2O)6] (C10H7SO3)·3H2O (Ln=Pr, Nd, Sm, Eu, Gd, Dy, Er, and Yb)

Abstract

Abstract Eight isomorphous 2-naphthalenesulfonato complexes of lanthanoids(III) (Pr, Nd, Sm, Eu, Gd, Dy, Er, and Yb) were synthesized, and the structures of five of them were determined by the single-crystal X-ray-diffraction method. They are monoclinic, with the space group of P21; the cell constants of the PrIII complex, for example, were a=18.228(8), b=7.498(4), c=14.177(9) Å, β=107.75(4)°, Z=2, and its final R value was 0.043. The unit-cell size of the complex decreases with the increase in the atomic number of the metal atom. The central metal atom is in a square-antiprism geometry and is octa-coordinated with two unidentate 2-naphthalenesulfonato ligands and six water–oxygen atoms. Nonligated oxygen atoms of the sulfonato ions form hydrogen-bonds with the coordinated and lattice water molecules to form a double-layered network along the ab-plane. All the naphthalene rings stand together to form hydrophobic sheets between the hydrogen-bonding networks.