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Names | |||
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IUPAC name
Carbonothioyl dichloride
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Other names
Thiophosgene; Thiocarbonyl chloride; Carbonothioic dichloride
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Identifiers | |||
3D model (JSmol)
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ChEBI | |||
ChemSpider | |||
ECHA InfoCard | 100.006.675 | ||
PubChem CID
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RTECS number |
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UNII | |||
CompTox Dashboard (EPA)
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Properties | |||
CSCl2 | |||
Molar mass | 114.97 g·mol−1 | ||
Appearance | Red liquid | ||
Odor | Persistent, choking odor | ||
Density | 1.50 g/cm3 | ||
Boiling point | 70 to 75 °C (158 to 167 °F; 343 to 348 K) | ||
Decomposes | |||
Solubility in other solvents | Reacts with amines and alcohols, soluble in polar organic solvents | ||
-50.6·10−6 cm3/mol | |||
Refractive index (nD)
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1.558 | ||
Structure | |||
planar, sp2, C2v | |||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards
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Highly toxic | ||
Flash point | 62 °C (144 °F; 335 K) | ||
Related compounds | |||
Related compounds
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Thiophosgene is a red liquid with the formula CSCl2. It is a molecule with trigonal planar geometry. There are two reactive C–Cl bonds that allow it to be used in diverse organic syntheses.[1]
CSCl2 is prepared in a two-step process from carbon disulfide. In the first step, carbon disulfide is chlorinated to give trichloromethanesulfenyl chloride (perchloromethyl mercaptan), CCl3SCl:
The chlorination must be controlled as excess chlorine converts trichloromethanesulfenyl chloride into carbon tetrachloride. Steam distillation separates the trichloromethanesulfenyl chloride, a rare sulfenyl chloride, and hydrolyzes the disulfur dichloride. Reduction of trichloromethanesulfenyl chloride produces thiophosgene:
Tin[2] and dihydroanthracene[3] have been used for the reducing agents.
CSCl2 is mainly used to prepare compounds with the connectivity CSX2 where X = OR, NHR.[4] Such reactions proceed via intermediate such as CSClX. Under certain conditions, one can convert primary amines into isothiocyanates. CSCl2 also serves as a dienophile to give, after reduction 5-thiacyclohexene derivatives. Thiophosgene is also known as the appropriate reagent in Corey-Winter synthesis for stereospecific conversion of 1,2-diols into alkenes.[5]
It forms a head-to-tail dimer upon irradiation with UV light:[6]
Unlike thiophosgene monomer, a red liquid, the photodimer, an example of a 1,3-dithietane, is a colourless solid.
Thisphosgene decomposes at 200 °C or above to form carbon disulfide and carbon tetrachloride.[7] It has also been observed decomposing to hydrogen sulfide, hydrogen chloride, and carbonyl sulfide gases via contact with human tissue.[8][failed verification]
CSCl2 is considered highly toxic. Inhalation of the substance can cause irritation of respiratory system, burns, delayed pulmonary edema and death.[9]