URANIUM CHLORIDE Property

Melting point:

590°

Boiling point:

bp760 791°

Density 

d425 4.725

solubility 

reacts with H2O; soluble in ethanol

form 

green octahedral crystals

color 

green octahedral crystals, crystalline

Water Solubility 

very soluble H2O, with decomposition [MER06]

EPA Substance Registry System

Uranium chloride (UCl4) (10026-10-5)

Hazard and Precautionary Statements (GHS)

URANIUM CHLORIDE Chemical Properties,Usage,Production

Production Methods

A bomb tube of ~ 1.5 cm I.D. is charged with 5.6 g of pure UOS and 10 ml of SOCI2 (freshly distilled in a vacuum); these are then thoroughly mixed. The sealed tube is heated for 7 days at 200 °C; the time required for completion of the reaction may be somewhat reduced if the tube is briefly cooled at regular intervals and the SO2 formed is permitted to escape. The product consists of UCl4, partially dissolved in SOCl2 and partially present as green crystals. The lower part of the bomb tube is cut off, and the entire contents are rinsed rapidly with some SOCl2 into a 100 ml ground-joint flask and distilled under reduced pressure (e.g., 140 mm) in a stream of dry N2 (or CO2) to remove the SOCl2. Finally, the brown adduct of SOCl2 and UCl4 is decomposed by heating at about 150°C until a pure green residue of UCl4 is obtained (half an hour is required). Yield: about 7.5 g (95%).

Chemical Properties

dark green octahedral crystal(s); oxidizes in air; decomposes in water; enthalpy of fusion 45.00 kJ/mol; prepared by the reaction UO3+3CCl3CCl=CCl2→UCl4+Cl2+3CCl2=CClOCl [KIR83] [CRC10] [MER06]

Production Methods

A bomb tube of ~ 1.5 cm I.D. is charged with 5.6 g of pure UOS and 10 ml of SOCI2 (freshly distilled in a vacuum); these are then thoroughly mixed. The sealed tube is heated for 7 days at 200 °C; the time required for completion of the reaction may be somewhat reduced if the tube is briefly cooled at regular intervals and the SO2 formed is permitted to escape. The product consists of UCl4, partially dissolved in SOCl2 and partially present as green crystals. The lower part of the bomb tube is cut off, and the entire contents are rinsed rapidly with some SOCl2 into a 100 ml ground-joint flask and distilled under reduced pressure (e.g., 140 mm) in a stream of dry N2 (or CO2) to remove the SOCl2. Finally, the brown adduct of SOCl2 and UCl4 is decomposed by heating at about 150°C until a pure green residue of UCl4 is obtained (half an hour is required). Yield: about 7.5 g (95%).

Safety Profile

Probably a poison. When heated to decomposition it emits toxic fumes of Cl-. See also URANIUM.