Layered structures of hydrated vanadium oxides. Part 3.—Aluminium-containing oxide (V1–xAlx)2O5–4x(OH)4x

Abstract

A new layered vanadium oxide containing aluminium (V_1–xAl_x)₂O_5–4x(OH)_4x(x= 0.18) with a layer spacing of 0.832 nm has been hydrothermally synthesized. The new phase, designated as phase II, exhibits the monoclinic system with a= 1.1679(9) nm, b= 0.3613(2) nm, c= 1.673(1) nm and β= 95.5(1)°; the c parameter is twice the layer period. X-Ray Rietveld analysis from the 00I reflections revealed the one-dimensional structure of the doublesheet M₂O₅ layer (M = V or Al) which is similar to those of the hydrated vanadium oxides studied previously. The replacement of V⁵⁺ by Al³⁺ results in the introduction of hydroxy groups which hold the M₂O₅ layers directly through O–H⋯O hydrogen bonds.