Thallium(III) hydroxide explained

Thallium(III) hydroxide,, also known as thallic hydroxide, is a hydroxide of thallium. It is a white solid.

Thallium(III) hydroxide is a very weak base; it dissociates to give the thallium(III) ion,, only in strongly acidic conditions.

Preparation

Thallium(III) hydroxide can be produced by the reaction of thallium(III) chloride with sodium hydroxide^[1] or the electrochemical oxidation of in alkaline conditions.^[2]

References

SynthesisThallium(I) hydroxide is obtained from the decomposition of thallium(I) ethoxide in water.[3]

CH3CH2OTl + H2O → TlOH + CH3CH2OHThis can also be done by direct reaction of thallium with ethanol and oxygen gas.

4 Tl + 2 CH3CH2OH + O2 → 2 CH3CH2OTl + 2 TlOHAnother method is the reaction between thallium(I) sulfate and barium hydroxide.

Tl2SO4 + Ba(OH)2 → 2 TlOH + BaSO4PropertiesThallous hydroxide is a strong base; it dissociates to the thallous ion, Tl+, except in strongly basic conditions. Tl+ resembles an alkali metal ion, such as Li+ or K+.

Notes and References

1. Glushkova, M. A. Reaction for the formation of the hydroxide of trivalent thallium. Zhurnal Neorganicheskoi Khimii, 1959. 4: 1657-1660.
2. Journal of the American Chemical Society. 73. 4. en. 0002-7863. April 1951. 1755–1756. 10.1021/ja01148a093. The Anodic Oxidation of Thallous Ion on the Rotating Platinum Microelectrode. 2020-06-01. Paul Delahay, G. L. Stiehl.