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

摘要

A new sodium vanadium(III) silicate, Na_3V(Si_4O_(11))·H_2O (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 P1-bar with a = 7.524(1) A, b = 8.755(2) A, c = 9.055(2) A, α = 62.486(3)°, β = 83.998(3)°, γ = 88.692(3)°, V = 525.9(2) A~3, and Z = 2. The [SiO_4] tetrahedra share corners with each other to form unbranched [Si_8O_(22)]~(12-) double chains. These chains are connected by isolated [VO_6] 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.