Name | Selenium Oxychloride |
Synonyms | Selenyl chloride Selenium Oxychloride Selenium oxidichloride Selenium(IV) dichlorideoxide Selenium(IV) oxychlorideSeleninyl chloride |
CAS | 7791-23-3 |
EINECS | 232-244-0 |
Molecular Formula | Cl2OSe |
Molar Mass | 165.87 |
Density | 2.43g/mLat 25°C(lit.) |
Melting Point | 9 °C |
Boling Point | 180°C(lit.) |
Flash Point | 176.4°C |
Water Solubility | decomposed in H2O to HCl, selenious acid; miscible with CCl4, CHCl3, CS2, benzene, toluene [MER06] |
Solubility | Miscible with chloroform, carbon disulphide and benzene. |
Appearance | Liquid |
Specific Gravity | 2.42 |
Color | Yellow |
Exposure Limit | ACGIH: TWA 0.2 mg/m3NIOSH: IDLH 1 mg/m3; TWA 0.2 mg/m3 |
Merck | 14,8435 |
Stability | Stable, but reacts with water and moisture. Incompatible with water, potassium, phosphorus. |
Sensitive | Moisture Sensitive |
Refractive Index | 1.651 |
Risk Codes | R14 - Reacts violently with water R23/25 - Toxic by inhalation and if swallowed. R33 - Danger of cumulative effects R35 - Causes severe burns R50/53 - Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S60 - This material and its container must be disposed of as hazardous waste. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S28 - After contact with skin, wash immediately with plenty of soap-suds. S20/21 - |
UN IDs | UN 2879 8/PG 1 |
WGK Germany | 3 |
RTECS | VS7000000 |
TSCA | Yes |
HS Code | 28121099 |
Hazard Class | 8 |
Packing Group | I |
Toxicity | LD50 s.c. in rabbits: 7 mg/kg (Wilber) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
Production method | 1. React dry HCl gas with selenium dioxide to generate dichloro selenite SeO2 · 2HCl, and dehydrate SeO2 · 2HCl with concentrated sulfuric acid to produce oxyselenium chloride. The reaction bottle is a round bottom flask with a volume of 150mL with a known weight. The HCl gas introduction tube is connected to the reaction bottle after passing through a safety bottle with a volume of 500mL. Place 50g of SeO2 in a reaction bottle, pass carefully dried HCl gas into the reaction bottle under the condition of moisture isolation, and shake the reaction bottle from time to time until SeO2 absorbs HCl and becomes SeO2 · 2HCl and dissolves (theoretical gain 33g). Add 10mL of concentrated sulfuric acid to the reaction bottle, shake the reaction bottle to fully mix it, and slowly heat it to 50 ℃, so that SeO2 · 2HCl is dehydrated for 10min, and the partially dehydrated product sinks to the lower layer. Transfer the liquid to a 100mL separatory funnel to separate the two layers of liquid. Add 5mL of concentrated sulfuric acid to the separated liquid product and treat it in the same way until the liquid is no longer stratified. It should be noted that insufficient dehydration or excessive sulfuric acid used during dehydration will reduce the yield. The completely dehydrated product can be dissolved in concentrated sulfuric acid, and a clear and transparent solution is formed when heated. When not completely dehydrated, concentrated sulfuric acid is added and shaken, turbidity will occur when heated. Before distillation, the product is cherry red because it contains SeCl2, which should be chlorinated by chlorine until it becomes grass yellow. At this time, SeCl2 changes to SeCl4, and SeCl4 reacts with SeO2 to form SeOCl2. Under the condition of isolating moisture, vacuum distillation is carried out twice by water suction pump. In order to prevent boiling, a capillary tube should be inserted into the distillation bottle. The first few milliliters of distillate are discarded each time and the distillation is stopped when a large amount of SeO2 accumulates. If the product is not yellowish, chlorine should be introduced again before the second distillation. Finally, the product is insulated from moisture and transferred to the glass ampoule, burned and stored. |
category | toxic substances |
toxicity classification | highly toxic |
acute toxicity | subcutaneous-rabbit LD50: 7 mg/kg |
flammability hazard characteristics | non-combustible substances; toxic hydrogen chloride and selenic acid vapor are released when exposed to heat or water |
storage and transportation characteristics | warehouse ventilation and low temperature drying; Store separately from alkalis, acids and food additives |
fire extinguishing agent | no water; carbon dioxide, foam, dry powder |
occupational standard | TLA-TWA 0.2 mg (selenium)/m3 |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |