Difference between revisions of "Sulfuryl chloride"

Latest revision as of 20:39, 6 August 2023

Sulfuryl chloride is a water sensitive inorganic compound with the formula SO₂Cl₂. Sulfuryl chloride is sometimes confused with thionyl chloride (SOCl₂), however the properties of the two chemicals are very different, as sulfuryl chloride is a source of chlorine, while thionyl chloride is a source of chloride ions.

Properties

Chemical

Sulfuryl chloride reacts exothermically with water to form hydrogen chloride and sulfuric acid:

2 H₂O + SO₂Cl₂ → 2 HCl + H₂SO₄

It will chlorinate various organic compounds, such as alkanes, alkenes, alkynes, aromatics, ethers. It will also chlorinate the metal center from organometallic compounds, when it is in a lower oxidation state.

Physical

Sulfuryl chloride is a colorless to yellowish liquid, with a strong poignant smell reminiscent of burned matches. It readily hydrolyzes in water and reacts with some organic solvents.

Availability

Sulfuryl chloride is sold by various chemical suppliers, but it is extremely difficult for the amateur chemist to acquire it.

Preparation

Sulfuryl chloride can be made by reacting sulfur dioxide and chlorine. The reaction is generally done without a solvent. Activated carbon or graphite is used as a catalyst, though UV light can speed up the reaction.^[1]

SO₂ + Cl₂ → SO₂Cl₂

If the reaction is done without a catalyst, at low temperatures, no product is obtained.^[2]

It can also be prepared by reacting disulfur dichloride with sulfur dioxide, at 170 °C. Elemental sulfur is produced as a byproduct.^[3]

S₂Cl₂ + SO₂ → SO₂Cl₂ + 2 S

Chlorination of chlorosulfuric acid will yield sulfuryl chloride. Various reagents, such as antimony(III) chloride, bismuth chloride, tin(IV) chloride can be used. Yields are given as 90%.^[4] If mercury or mercury(II) sulfate are used instead, the yield is only around 60%.^[5][6]

4 SOCl₂ + Hg → S₂Cl₂ + HgCl₂ + 2 SO₂Cl

Aluminium chloride will react with sulfur trioxide to yield sulfuryl chloride.^[7][8]

Oxidation of thionyl chloride with certain metal oxides, like manganese dioxide, lead(II,IV) oxide, lead(IV) oxide, barium peroxide, also yields sulfuryl chloride. Reaction takes place at 150 °C over several hours:^[9]

2 SOCl₂ + MnO₂ → SO₂Cl₂ + MnCl₂ + SO₂

4 SOCl₂ + Pb₃O₄ → SO₂Cl₂ + 3 PbCl₂ + 3 SO₂

2 SOCl₂ + PbO₂ → S₂Cl₂ + PbCl₂ + 3 SO₂Cl₂

2 SOCl₂ + BaO₂ → S₂Cl₂ + BaCl₂ + 3 SO₂Cl₂

If mercury(II) oxide is used, a large excess of thionyl chloride must be used. If equimolar amounts of HgO and thionyl chloride are used instead, only sulfur dioxide is produced.^[10]

5 SOCl₂ + HgO → S₂Cl₂ + HgCl₂ + 3 SO₂Cl₂

SOCl₂ + HgO → HgCl₂ + SO₂

A less known route is given in literature as the reaction between sulfur trioxide and chromyl chloride.^[11][12]

SO₃ + CrO₂Cl₂ → SO₂Cl₂ + CrO₃

Thermal decomposition of sodium chlorosulfate (sodium salt of chlorosulfuric acid) is claimed to yield sulfuryl chloride:^[13]

2 NaSO₃Cl → SO₂Cl₂ + Na₂SO₄

Other sources indicate that sodium pyrosulfate is produced as side product.^[14][15]

Projects

• Make chlorobenzene
• Make alkyl chlorides

Handling

Safety

Sulfuryl is extremely corrosive and toxic. It fumes in (moist) air and hydrolyzes in water.

Storage

Sulfuryl chloride should be stored in glass bottles, preferably amber glass, away from any moisture, best in a corrosive chemicals cabinet.

Disposal

Sulfuryl chloride can be neutralized with an alkaline solution. The reaction will release plenty of corrosive fumes, so it's best to do this outside.

References

1. ↑ F. Fehér (1963). "Sulfuryl Chloride". In G. Brauer (ed.). Handbook of Preparative Inorganic Chemistry, 2nd Ed. Vol. 1. NY,NY: Academic Press. pp. 382–384
2. ↑ Schulze, H.; Journal fuer Praktische Chemie (Leipzig); vol. 24; (1881); p. 168 - 183
3. ↑ Besson, A.; Fournier, L.; Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences; vol. 150; (1910); p. 1752 - 1754
4. ↑ Ruff, O.; Ber.; vol. 34; (1901); p. 3509 - 3515
5. ↑ Bert, L.; Bulletin de la Societe Chimique de France; vol. 31; (1922); p. 1264 - 1270
6. ↑ North, H. B.; Journal of the American Chemical Society; vol. 32; (1910); p. 184 - 187
7. ↑ Rose, H.; Annalen der Physik (Weinheim, Germany); vol. 44; (1838); p. 291 - 327
8. ↑ Beckmann, E.; Z. Anorg. Chem.; vol. 77; (1912); p. 90 - 102 ; (from Gmelin)
9. ↑ H. B. North and A. M. Hageman, J. Am. Chem. Soc. 1913, 35, 5, 543–546
10. ↑ North, H. B.; Journal of the American Chemical Society; vol. 32; (1910); p. 184 - 187
11. ↑ S: MVol.B3; 131, page 1807 - 1808; (from Gmelin)
12. ↑ Luchinskii, G. P.; Likhacheva, A. I.; Zhurnal obshchei Khim. (russ.); vol. 7; (1937); p. 405 - 414
13. ↑ Luchinskii, G. P.; Zhurnal obshchei Khim. (russ.); vol. 8; (1938); p. 1864 - 1869
14. ↑ Puskaric, E.; Heubel, J.; Comptes Rendus des Seances de l'Academie des Sciences, Serie C: Sciences Chimiques; vol. 267; (1968); p. 965 - 967
15. ↑ Puskaric, E.; Jaeger, R. de; Heubel, J.; Revue de Chimie Minerale; vol. 12; (1975); p. 374 - 381

Relevant Sciencemadness threads

• Decomposition of sulfuryl chloride