Sulfur dichloride
From Wikipedia, the free encyclopedia
| Sulfur dichloride | |
|---|---|
 |
|
| General | |
| Systematic name | Sulfur(II) chloride |
| Other names | sulfur dichloride |
| Molecular formula | SCl2 |
| SMILES | ClSCl |
| Molar mass | 102.97 g mol−1 |
| Appearance | red liquid at STP |
| CAS number | [10545-99-0] |
| Properties | |
| Density and phase | 1.621 g cm−3 |
| Solubility in water | decomp with loss of HCl |
| Other solvents | benzene, chlorocarbons |
| Melting point | −121.0 °C (? K) |
| Boiling point | 59 °C (? K) |
| Structure | |
| Coordination geometry |
C2v |
| Dipole moment | ? D |
| Hazards | |
| MSDS | External MSDS |
| Main hazards | ? |
| NFPA 704 | |
| R/S statement | R: ? S: ? |
| RTECS number | ? |
| Supplementary data page | |
| Structure and properties |
n, 1.5570 |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Related compounds | Sulfur tetrafluoride, SF4 Sulfuryl chloride, SO2Cl2 Thionyl chloride, SOCl2 Disulfur dichloride, S2Cl2 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
|
Sulfur dichloride is SCl2. This cherry-red liquid is produced by the chlorination of either elemental sulfur or disulfur dichloride, S2Cl2. Separation of SCl2 from S2Cl2 is possible via distillation with PCl3 to form an azeotrope of 99% purity.
Contents |
[edit] Chlorination of sulfur
The chlorination of sulfur occurs in a series of steps, some of which are:
-
- S8 + 4Cl2 → 4S2Cl2; ΔH = −58.2 kJ/mol
- S2Cl2 + Cl2 → 2SCl2; ΔH = −40.6 kJ/mol
The addition of Cl2 to S2Cl2 is considered to proceed via a mixed valence intermediate Cl3S-SCl. SCl2 undergoes even further chlorination to give SCl4, but this species is unstable at near room temperature. It is likely that several SxCl2 exist where x > 2.
[edit] Use of SCl2 in chemical synthesis
- SCl2 is occasionally useful in organic synthesis, an illustrative application is its addition to 1,5-cyclooctadiene to give a bicyclic thioether. In an infamous reaction, SCl2 adds ethylene to give mustard gas (which is not a gas, but a liquid).
- SCl2 is a precursor to SF4.
- SCl2 is a key reagent in the preparation of S-N compounds related to S4N4.
- SCl2 reacts with H2S to give "higher" sulfanes such as S3H2.
[edit] Safety considerations
SCl2 hydrolyzes potentially dangerously with release of HCl. Old samples contain Cl2.
[edit] References
M. Schmidt, W. Siebert "Sulphur" Comprehensive Inorganic Chemistry Vol. 2, ed. A.F. Trotman-Dickenson. 1973.
