Thallium hydride

Thallium hydride

Names
Systematic IUPAC name Thallane (substitutive) Trihydridothallium (additive)
Identifiers
CAS Number	82391-14-8
ChEBI	CHEBI:30437 Y
ChemSpider	123171 Y
Gmelin Reference	362119
Jmol 3D model	Interactive image
PubChem	139662
InChI InChI=1S/Tl.3H Y Key: NWUWMQRSDSSETA-UHFFFAOYSA-N Y
SMILES [TlH3]
Properties
Chemical formula	TlH 3
Molar mass	207.4071 g mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Thallium hydride (systematically named thallium trihydride) is an inorganic compound with the empirical chemical formula TlH
₃. It has not yet been obtained in bulk, hence its bulk properties remain unknown. However, molecular thallium hydride has been isolated in solid gas matrices. Thallium hydride is mainly produced for academic purposes.

Thallium hydride is the simplest thallane. Thallium is the heaviest member of the Group 13 metals; the stability of group 13 metal hydrides decreases with increasing periodic number. This is commonly attributed to poor overlap of the metal valence orbitals with that of the 1s orbital of Hydrogen. Despite encouraging early reports, it is unlikely that a thallium hydride species has been isolated. Thallium hydrides have been observed only in matrix isolation studies; the infrared spectrum was obtained in the gas phase by laser ablation of thallium in the presence of hydrogen gas. This study confirmed aspects of ab initio calculations conducted by Schwerdtfeger which indicated the similar stability of thallium and indium hydrides. There has not been a confirmed isolation of a thallium hydride complex to date.

History

In 2004 American chemist, Lester Andrews synthesised thallium hydride for the first time. This reaction sequence consisted of atomisation of thallium, followed by cryogenic co-deposition with hydrogen, and concluded with shortwave ultraviolet irradiation.