Intercalation compounds of (diphosphato)oxotungsten(VI), [WO(P2O7)]

Abstract

Reduction of [WO(P₂O₇)] in aqueous solution with strong reducing agents results in the uptake of cations and water molecules in the interalayer spaces and expansion of the basal spacing. The product Na_xWO(P₂O₇)·nH₂O (0.80 ⩽x⩽ 1.41) was produced with Na₂S₂O₄ solution. At x > 1.1 a hydrated phase with a basal spacing of 10.8 Å and n= 1.0 was obtained, and at x < 1.1 three hydrated states with basal spacings of 11.5, 10.8, and 10.4 Å were found, depending on the humidity. The basal spacing of the unhydrated phase is 9.5 Å at any value of x. Upon reduction with acidified SnCl₂ solution, Sn²⁺ and H⁺ were taken up into the interlayer spaces to form Sn²⁺_xH_yWO(P₂O₇)·nH₂O with a basal spacing of 12.2 Å. The sum (2x+y) ranged from 0.46 to 0.80.