Jump to content

Thorium(IV) chloride

From Wikipedia, the free encyclopedia
(Redirected from Thorium tetrachloride)
Thorium(IV) chloride
Thorium(IV) chloride structure
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.039 Edit this at Wikidata
EC Number
  • 233-056-1
RTECS number
  • XO6475000
UNII
  • InChI=1S/4ClH.Th/h4*1H;/q;;;;+4/p-4
    Key: WEQHQGJDZLDFID-UHFFFAOYSA-J
  • Cl[Th](Cl)(Cl)Cl
Properties
ThCl4
Molar mass 373.849 g/mol
Appearance white needles
hygroscopic
Density 4.59 g/cm3, solid
Melting point 770 °C (1,420 °F; 1,040 K)
Boiling point 921 °C (1,690 °F; 1,194 K)
Structure
tetragonal
Hazards
Lethal dose or concentration (LD, LC):
332 mg/kg intraperitoneal mouse
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Thorium(IV) chloride describes a family of inorganic compounds with the formula ThCl4(H2O)n. Both the anhydrous and tetrahydrate (n = 4) forms are known. They are hygroscopic, water-soluble white salts.

Structures

[edit]
Alternative view of the structure of solid ThCl4.

The structure of thorium(IV) chloride features 8-coordinate Th centers with doubly bridging chloride ligands.[1]

Synthesis

[edit]

ThCl4 was an intermediate in the original isolation of thorium metal by Jons Jacob Berzelius.[2]

Thorium(IV) chloride can be produced in a variety of ways. One method is a carbothermic reaction, 700 °C to 2600 °C, involving thorium oxides and carbon in a stream of chlorine gas:

ThO2 + 2 C + 4 Cl2 → ThCl4 + 2 CO

The chlorination reaction can be effected with carbon tetrachloride:[3][4]

Th(C2O4)2 + CCl4 → ThCl4 + 3 CO + 3 CO2

In another two-step method, thorium metal reacts with ammonium chloride:

Th + 6 NH4Cl → (NH4)2ThCl6 + 4 NH3 + 2 H2

The hexachloride salt is then heated at 350 °C under a high vacuum to produce ThCl4.[5]

Reactions

[edit]
Lewis base adducts

ThCl4 reacts with Lewis bases to give molecular adducts, such as ThCl4(DME)2 and ThCl4(TMEDA)2.[5]

Reduction to Th metal

Thorium(IV) chloride is an intermediate in the purification of thorium, which can be affected by:

  1. Reduction of ThCl4 with alkali metals.
  2. Electrolysis of anhydrous thorium(IV) chloride in fused mixture of NaCl and KCl.
  3. Ca reduction of a mixture of ThCl4 with anhydrous zinc chloride.[6]

References

[edit]
  1. ^ Mason, J. T.; Jha, M. C.; Chiotti, P. (1974). "Crystal Structures of ThCl4 Polymorphs". Journal of the Less Common Metals. 34: 143–151. doi:10.1016/0022-5088(74)90224-0.
  2. ^ Weeks, Mary Elvira (1932-07-01). "The Discovery of the Elements. XI. Some Elements Isolated with the Aid of Potassium and Sodium: Zirconium, Titanium, Cerium, and Thorium". Journal of Chemical Education. 9 (7): 1231. Bibcode:1932JChEd...9.1231W. doi:10.1021/ed009p1231. ISSN 0021-9584.
  3. ^ Brauer, Georg (1963). Handbook Of Preparative Inorganic Chemistry. New York: Academic Press.
  4. ^ Gutierrez, R. L.; Herbst, R. J. (October 1979). "Preliminary Fabrication Studies of Alternative LMFBR Carbide Fuels". Los Alamos Scientific Laboratory. doi:10.2172/5688597.
  5. ^ a b Cantat, Thibault; Scott, Brian L.; Kiplinger, Jaqueline L. (2010-01-25). "Convenient Access to the Anhydrous Thorium Tetrachloride Complexes ThCl4(DME)2, ThCl4(1,4-dioxane)2 and ThCl4(THF)3.5 using Commercially Available and Inexpensive Starting Materials". Chemical Communications. 46 (6): 919–21. doi:10.1039/b923558b. ISSN 1364-548X. PMID 20107650.
  6. ^ "Periodic Table of Elements: Los Alamos National Laboratory". periodic.lanl.gov. Retrieved 2016-04-29.