title: Synthesis and structural characterization of a new nanoporous-like Keggin heteropolyanion salt: K3(H2O)4[H2SiVW11O40](H2O)8+x.
abstract: Single crystals of the potassium salt K3(H2O)4[H2SiVW11O40](H2O)8+x of the vanadium monosubstituted alpha-Keggin dodecatunsgstosilicate were grown from an aqueous solution and analyzed by EDS, XRD, vibration and electronic spectroscopy, and 1H, 51V, and 29Si solid-state NMR spectroscopy. Results indicate the formation of a nanoporous-like compound of hexagonal symmetry (space group P62) with large, water-filled channels running along the c axis. A uniform distribution of vanadium over the 12 metal sites of the alpha-Keggin anion is observed by XRD. Two different neighborhoods were characterized by 51V NMR in a 2:1 ratio (deltaiso=-546.3 and -536.2 ppm), in accordance with a difference in the number of potassium ions in the second coordination shell of vanadium.
authors: Instituto de Química, Universidade Federal do Rio de Janeiro, Brazil.
authors: Rodrigo
authors: R
authors: de Paiva Floro Bonfim
authors: Luiza Cristina
authors: LC
authors: de Moura
authors: Hélène
authors: H
authors: Pizzala
authors: Stefano
authors: S
authors: Caldarelli
authors: Sébastien
authors: S
authors: Paul
authors: Jean Guillaume
authors: JG
authors: Eon
authors: Olivier
authors: O
authors: Mentré
authors: Mickaël
authors: M
authors: Capron
authors: Laurent
authors: L
authors: Delevoye
authors: Edmond
authors: E
authors: Payen