Crystal chemistry of the saccharinato complexes of trivalent lanthanides and Yttrium

O. E. PIRO; E. E. CASTELLANO; E. J. BARAN

Zeitschrift für Anorganische und Allgemeine Chemie

WILEY-VCH

Año: 2002 vol. 628 p. 612 - 619

Abstract. Saccharinate complexes of the fourteen trivalent lanthanide cations and Y(III) were prepared by reaction between the respective lanthanide carbonates and saccharin in aqueous solution. Their crystal structures were determined by single crystal X-ray diffractometry. They represent three different structural types. The first family, of composition [Ln(sac)(H2O)8](sac)2·H2O (sac 5 anion of saccharin; Ln = La,Ce,Pr,Nd.Sm,Eu), belongs to the monoclinic space group P21/c with Z = 4 and the Ln(III) cation is in a tricapped trigonal prismatic environment with nine-fold oxygen coordination. The second group of composition [Ln(sac)2(H2O)6]-(sac)(Hsac)·4H2O with Ln = Gd,Dy,Ho,Er,Yb,Lu,and Y, pertains to the triclinic P1¯- space group, with Z = 2 and constitutes a new example of complexes containing simultaneously saccharin and its anion in the lattice. The Tm(III) and Tb(III) compounds, which are also triclinic (space group P1¯- and Z = 2) present two closely related structures conformed by three and two [Ln(sac)(H2O)7]21 crystallographically independent complexes, respectively, with the [Tm(sac)(H2O)7]3(sac)6·9H2O and [Tb(sac)(H2O)7]2(sac)4·6H2O composition. For all the heavier lanthanides (Gd-Lu) and yttrium the cation presents eight-fold oxygen coordination, with the ligands at the corners of a slightly distorted square Archimedean antiprism.