Thallium oxide
Encyclopedia
Thallium oxide is the inorganic compound
of thallium
and oxygen
with the formula Tl2O in which thallium is in its +1 oxidation state
. It is black and produces a basic
yellow solution of thallium(I) hydroxide
(TlOH) when dissolved in water. It is formed by heating solid TlOH or Tl2CO3 in the absence of air. Thallium oxide is used to make special high refractive index
glass
. Thallium oxide is a component of several high temperature superconductor
s. Thallium(I) oxide reacts with acid
s to make thallium(I) salts.
Tl2O adopts the anti-cadmium iodide
motif in the solid state. In this way, the Tl(I) centers are pyrdamidal and the oxide centers are octahedral
.
Thallium(I) oxide, like all thallium compounds, is highly toxic.
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...
of thallium
Thallium
Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray poor metal resembles tin but discolors when exposed to air. The two chemists William Crookes and Claude-Auguste Lamy discovered thallium independently in 1861 by the newly developed method of flame spectroscopy...
and oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
with the formula Tl2O in which thallium is in its +1 oxidation state
Oxidation state
In chemistry, the oxidation state is an indicator of the degree of oxidation of an atom in a chemical compound. The formal oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. Oxidation states are typically represented by...
. It is black and produces a basic
Base (chemistry)
For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...
yellow solution of thallium(I) hydroxide
Thallium(I) hydroxide
Thallium hydroxide, also called thallous hydroxide, TlOH, is a hydroxide of thallium, with thallium in oxidation state +1. Thallous hydroxide is a strong base; it is changed to thallous ion, Tl+, except in strongly basic conditions.-References:...
(TlOH) when dissolved in water. It is formed by heating solid TlOH or Tl2CO3 in the absence of air. Thallium oxide is used to make special high refractive index
Refractive index
In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....
glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
. Thallium oxide is a component of several high temperature superconductor
High-temperature superconductivity
High-temperature superconductors are materials that have a superconducting transition temperature above . From 1960 to 1980, 30 K was thought to be the highest theoretically possible Tc...
s. Thallium(I) oxide reacts with acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
s to make thallium(I) salts.
Tl2O adopts the anti-cadmium iodide
Cadmium iodide
Cadmium iodide, CdI2, is a chemical compound of cadmium and iodine. It is notable for its crystal structure, which is typical for compounds of the form MX2 with strong polarization effects.-Uses:...
motif in the solid state. In this way, the Tl(I) centers are pyrdamidal and the oxide centers are octahedral
Octahedral molecular geometry
In chemistry, octahedral molecular geometry describes the shape of compounds where in six atoms or groups of atoms or ligands are symmetrically arranged around a central atom, defining the vertices of an octahedron...
.
Thallium(I) oxide, like all thallium compounds, is highly toxic.