Lanthanide-Containing 22-Tungsto-2-germanates [Ln(GeW11O39)2]13–: Synthesis, Structure, and Magnetic Properties

• Published in: Inorganic chemistry Vol. 59; no. 7; pp. 4340 - 4348
• Main Authors: Mougharbel, Ali S, Bhattacharya, Saurav, Bassil, Bassem S, Rubab, Amna, van Leusen, Jan, Kögerler, Paul, Wojciechowski, Jakub, Kortz, Ulrich
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06.04.2020
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.9b03271

We report on the synthesis and structural characterization of two series of lanthanide-containing 22-tungsto-2-germanates. The first series corresponds to a family of polyanions with the formula [Ln­(β 2 -GeW11O39)2]13– (LnIII = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Gd (6), Dy (7)), and the second series corresponds to a family with the formula [Ln­(β 2 -GeW11O39)­(α-GeW11O39)]13– (LnIII = Ho (8), Er (9), Tm (10)). All compounds were characterized in the solid state by single-crystal and powder XRD, IR, TGA, and SQUID magnetometry. The polyanions were synthesized in aqueous medium by direct reaction of the monolacunary [β 2 -GeW11O39]8– POM precursor with the corresponding lanthanide salts. The structure of the polyanions consists of an 8-coordinated lanthanide ion in a square-antiprismatic geometry, which is sandwiched either between two [β 2 -GeW11O39]8– units for 1–7 or between a [β 2 -GeW11O39]8– and a [α-GeW11O39]8– unit for 8–10. Furthermore, the effect of the central paramagnetic lanthanide ion on the magnetic behavior of the polyanions was investigated, with the erbium-derivative [Er­(β 2 -GeW11O39)­(α-GeW11O39)]13– (9) showing single-molecule magnet (SMM) behavior.