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| | TELLURIUM TETRABROMIDE Basic information |
| | TELLURIUM TETRABROMIDE Chemical Properties |
| Melting point | ~380 °C(lit.) | | Boiling point | 420 °C(lit.) | | density | 4.3 g/mL at 25 °C(lit.) | | Fp | 420°C | | solubility | reacts with H2O; soluble in ethyl ether | | form | beads | | color | yellow-orange monoclinic
crystals, crystalline | | Water Solubility | It reacts with water and ethanol. | | Sensitive | Moisture Sensitive | | Merck | 14,9125 | | Exposure limits | ACGIH: TWA 0.1 mg/m3
NIOSH: IDLH 25 mg/m3; TWA 0.1 mg/m3 | | CAS DataBase Reference | 10031-27-3(CAS DataBase Reference) | | EPA Substance Registry System | Tellurium bromide (TeBr4), (T-4)- (10031-27-3) |
| Hazard Codes | C | | Risk Statements | 34 | | Safety Statements | 22-26-27-36/37/39-45 | | RIDADR | UN 3260 8/PG 2 | | WGK Germany | 3 | | TSCA | Yes | | HazardClass | 8 | | PackingGroup | II |
| | TELLURIUM TETRABROMIDE Usage And Synthesis |
| Description | Tellurium tetrabromide is a iron-gray crystalline substance; stable even in moist air. Decomposes on heating, giving off I2. Hydrolyzed slowly in cold water, rapidly in warm water, forming TeO2 and HI.
| | Chemical Properties | Yellow crystals. Soluble in a little water (decomposes in excess
water). | | Uses | Tellurium tetrabromide?it acts as a chemical and organic intermediate. It is also acts a conductor. | | Preparation |
Pure Te (5 g.) is introduced through adapter a into the elongated reaction flask A of the apparatus shown in Fig.1. Adapter a is connected to a N2 purification train which furnishes either pure dry N2 or N2 containing bromine vapor. For the latter, the gas stream may be passed through a wash bottle containing dry Br2 , followed by a U tube containing P2O5-glass wool. First, the apparatus in purged with pure N2. Then A is cooled with ice water and the N2 -Br2 mixture is introduced. A portion of the Br2 condenses on the Te and reacts quietly with it, while the remainder is retained in the empty U tube D, cooled with an ice-salt mixture. The difference between the weight loss of the Br2 wash bottle and the weight of the condensate in D indicates the amount of bromine remaining in A. When this becomes about twice the amount needed for quantitative conversion to TeBr4, the gas stream is interrupted, stopcock C is closed, and the product slurry is allowed to stand at room temperature for several hours (better overnight) in order to complete the reaction. Then C is reopened and the excess bromine is purged by a stream of N2 while A is simultaneously heated to 50℃. To purify the product, it is sublimed in vacuum. Gas inlet tube a is sealed off at d, the whole apparatus is tilted to a horizontal position, and ground glass joint E is connected to an aspirator through a P2O5 drying tube. During evacuation, A is heated to sublimation temperature (about 350℃) with an electric furnace. Any black condensate which may separate in B at 200℃ is vaporized by heating with a burner. The subsequently deposited yellow to orange-red powder is quite pure TeBr4; if necessary, this can be further purified by an analogous sublimation in high vacuum.
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| | TELLURIUM TETRABROMIDE Preparation Products And Raw materials |
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