Иттрий сульфат октагидрат

Описание

Yttrium(III) sulfate octahydrate, with the chemical formula Y2(SO4)3-8H2O, consists of infinite layers parallel to (10\overline 1), with [Y(H2O)4(SO4)3/2] being the only repeating unit. The layers are connected to each other using only moderately strong hydrogen bonds. The trivalent yttrium cation is coordinated by eight O-atoms from four sulfate groups and four water molecules in a distorted square antitetrahedron [YO8]. It is of the same structural type as the rare earth sulfate octahydrate^[1].

Figure 1. View perpendicular to the (10 1) layer of the title compound, with [Y(H 2 O) 4/1 (SO 4 (1)) 3/3 (SO 4 (2)) 1/2 ] as the repeat unit. Key: [SO 4 ] tetrahedra (yellow), [YO 8 ] antiprisms (red), oxygen (blue) and hydrogen (light grey) atoms.

Химические свойства

Small, reddish-white, monosymmetric crystals. D 2.558, loses 8H2O at 120C, decomposes 700C. Soluble in concentrated sulfuric acid; sparingly soluble in water; insoluble in alkalies.

Физические свойства

Red monoclinic crystals; density 2.59 g/cm³; loses all its water molecules at 120°C; decomposes at 700°C; sparingly soluble in water, less soluble in hot water; dissolves in concentrated sulfuric acid forming Y(HSO4)3; insoluble in alkalis; forms double salts with alkali sulfates.

Использование

Yttrium sulfate is used in making many yttrium salts.

Подготовка

Yttrium sulfate is produced as an intermediate in recovering yttrium from monazite or xenotime (see Yttrium, Recovery). Rare earth sulfates are separated on a cation exchange resin bed. Yttrium fraction is purified by fractional crystallization. Alternatively, yttrium sulfate may be prepared by reacting yttrium oxide with sulfuric acid.