Thallium oxide is a solid, very dark brown and odourless chemical substance. Thallium oxide is stable under normal temperatures and pressures.
It is insoluble in water. Thallium oxide has been used to produce glasses with a high index of refraction.
Analysis (testing for ozone), artificial gem, optical
glass of high refractive index.
Thallium(III) oxide is used in organic synthesis and as an analytical reagent
Thallium oxide is produced either by the chlorine-induced
oxidation of thallous nitrate in an aqueous potassium hydroxide
solution, followed by thallium reaction with oxygen, or
from hydrogen peroxide and an alkaline thallium(I) solution
; or either form of thallous oxide oxidation. The
oxide is an intermediate that can be formed during annealing
or heating of semiconductors in air.
Brown powder. Insoluble in water.
A mixture of THALLIUM(III) OXIDE and antimony sulfide or sulfur explodes when ground in a mortar [Mellor 5:421 1946-47]. THALLIUM(III) OXIDE is decomposed by HCl with evolution of chlorine gas, and by H2SO4 with evolution of oxygen.
Poison by ingestion, intraperitoneal, and intravenous routes. Combustible by chemical reaction. Evolves O2 @ 875°C. Mixtures with sulfur orantimony trisulfide explode when ground. Hydrogen sulfide ignites and may explode weakly on contact with the oxide. When heated to decomposition it emits toxic fumes of T1. See also THALLIUM COMPOUNDS.
