Synthesis and characterization of an open framework vanadium silicate (VSH-16Na)

Anew sodium vanadium(III) silicate, Na3V(Si4O11).H2O (VSH-16Na(1)) has been synthesized hydrothermally and its structure determined by single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P (1) over bar with a = 7.524(1) Angstrom, b = 8.755 (2) Angstrom, c = 9.055(2) Angstrom, a = 62.486(3)degrees, beta = 83.998(3)degrees, gamma = 88.692(3)degrees, V = 525.9(2) Angstrom(3), and Z = 2. The [SiO4] tetrahedra share corners with each other to form unbranched [Si8O22](12-) double chains. These chains are connected by isolated [VO6] octahedra to form an open framework structure with eight-ring channels. The magnetic susceptibility data-show Curie-Weiss behavior down to 5 K and are consistent with the trivalent state of the vanadium atoms. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.