Details

Autor(en) / Beteiligte

• Merca, Alice
• Schnack, Jurgen
• Slageren, Joris van
• Glaser, Thorsten
• Bogge, Hartmut
• Hoeke, Veronika
• Lage, Mechtild
• Muller, Achim
• Krebs, Bernt

Titel

Systematic Study of the Interaction Between V super(IV) Centres and Ln super(III) Ions in Well Defined {V(ProQuest: Formulae and/or non-USASCII text omitted)Ln super(III)}{As super(III)W9O super(33)} sub(2) Sandwich-Type Clusters: Part 2

Ist Teil von

• Journal of cluster science, 2013-12, Vol.24 (4), p.979-988

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The gadolinium (Gd) member of a new type of heteropolytungstates that contain one lanthanide and two transition metal ions in a triangular arrangement is reported. The compound NaK sub(6)Gd sub(0.33) [((VO) sub(2)Gd(H sub(2)O) sub(4)K sub(2)(H sub(2) O) sub(2)(Na)(H sub(2)O) sub(2))([alpha]-B-AsW sub(9)O sub(33))2][middot]24H sub(2) (1) was prepared from acidified aqueous solutions of Na sub(2)WO sub(4)[middot]2H sub(2)O, As sub(2)O sub(3) and VOSO sub(4)[middot]5H sub(2)O to which Gd super(3+) ions were added. The single crystal X-ray structure analysis (monoclinic, space group P2 sub(1)/m) shows that the anion consists of two [[alpha]-B-As super(III)W sub(9)O sub(33)] super(9-) trilacunary Keggin-type units linked by two one Gd super(3+) as well as weakly by two K super(+) and one Na super(+) ions, resulting in a sandwich-type structure with idealized C sub(2v), symmetry. The problem of positioning crystal lattice and special polyoxometalate sites with different cations is discussed also in connection with supramolecular chemistry aspects and as an option for further research. A fit of the magnetic susceptibility yielded exchange coupling constants of J sub(vv) = -2.55 cm super(-1) (anti-ferromagnetic) between the vanadium ions and JGdv = 0.6 cm super(-1) (ferromagnetic) between the Gd and each of the two vanadium ions. The complete magnetochemical analysis also revealed a partial occupancy of the Na super(+) sites in the counter-cation-water system by Gd super(3+) ions (0.33 Gd super(3+) ions in total).