977. Barium Hydroxide

Nomenclature

CAS number: 17194-00-2
Barium hydroxide (Ba(OH)2); barium dihydroxide; activated barium hydroxide; caustic baryta.
BaH2O2; mol wt 171.34.
Ba 80.15%, H 1.18%, O 18.68%.
Ba(OH)2.

Description and references

Reacts as base/nucleophile in organic syntheses. Prepn: Gmelins, Barium (8th ed) 30, 106-111 and suppl. 175-177, 289 (1960). Thermal dehydration and decomposition study: G. M. Habashy, G. A. Kolta, J. Inorg. Nucl. Chem. 34, 57 (1972). Use as a catalyst in organic synthesis: J. Barrios et al., J. Catal. 112, 528 (1988); I. Paterson et al., Synlett 1993, 774; Y.-D. Gong et al., J. Org. Chem. 63, 4854 (1998); R. S. Varma et al., Tetrahedron Lett. 39, 8437 (1998). Review of synthetic applications: S. Jeanmart, Synlett 2002, 1739-1740. Review of toxicology and human exposure: Toxicological Profile for Barium and Compounds (PB93-110658, 1992) 163 pp.

Derivative

Monohydrate.

Nomenclature

CAS number: 22326-55-2
Dried barium hydroxide.
BaH2O2.H2O; mol wt 189.36.
Ba 72.52%, H 2.13%, O 25.35%.

Properties

Obtained by heating commercial Ba(OH)2.8H2O at 200°. White powder. Poisonous. d 3.743. Slightly sol in water; sol in dil acids.

Derivative

Octahydrate.

Nomenclature

CAS number: 12230-71-6
BaH2O2.8H2O; mol wt 315.46.
Ba 43.53%, H 5.75%, O 50.72%.

Properties

Most common form of the hydroxide, readily available commerically. Transparent crystals or white masses. Very alkaline; rapidly absorbs CO2 from air, becoming incompletely sol in water. Poisonous. mp 78°. Freely sol in water, methanol; slightly sol in ethanol. Practically insol in acetone. Keep tightly closed.

Use

In manuf of alkali, glass; in synthetic rubber vulcanization, in corrosion inhibitors, pesticides, sugar industry; boiler scale remedy; refining animal and vegetable oils; softening water. Catalyst in organic synthesis. Carbonate-free base in alkalimetry.