sulfur tetrachloride
{{Chembox
| ImageFile = Sulfur tetrachloride.svg
| ImageSize = 150px
| IUPACName = Sulfur(IV) chloride
| OtherNames =
|Section1={{Chembox Identifiers
| CASNo = 13451-08-6
| PubChem = 13932016
| ChemSpiderID =
| SMILES = ClS(Cl)(Cl)Cl
| InChI = 1/Cl4S/c1-5(2,3)4
}}
|Section2={{Chembox Properties
| Formula = SCl4
| MolarMass = 173.87
| Appearance = White powder
| Density =
| MeltingPtC = -31
| BoilingPtC = -20
| BoilingPt_notes = (decomposes)
| Solubility = soluble in water
}}
|Section3={{Chembox Hazards
| GHSPictograms = {{GHS05}}{{GHS09}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|314|400}}
| PPhrases = {{P-phrases|260|264|273|280|301+330+331|303+361+353|304+340|305+351+338|310|321|363|391|405|501}}
| MainHazards =
| FlashPt =
| AutoignitionPt =
}}
}}
Sulfur tetrachloride is an inorganic compound with chemical formula SCl4. It has only been obtained as an unstable pale yellow solid. The corresponding SF4 is a stable, useful reagent.
Preparation and structure
It is obtained by treating sulfur dichloride with chlorine at 193 K:
:{{chem2 | SCl2 + Cl2 -> SCl4 }}
It melts with simultaneous decomposition above −20 °C.Georg Brauer: Handbuch der Präparativen Anorganischen Chemie. {{in lang|de}}
Its solid structure is uncertain. It is probably the salt SCl3+Cl−, since related salts are known with noncoordinating anions.{{Greenwood&Earnshaw2nd}}{{cite journal | doi = 10.1021/ic00226a012 | title = Preparations, Raman spectra, and crystal structures of (SCl3)(SbCl6), (SeCl3)(SbCl6), (SBr1.2Cl1.8)(SbCl6), (TeCl3)(AlCl4) (Triclinic modification), (TeCl3)(SbF6), (TeCl3)(AsF6), and (TeF3)2(SO4) | date = 1986 | last1 = Christian | first1 = Beverly H. | last2 = Collins | first2 = Michael J. | last3 = Gillespie | first3 = Ronald J. | last4 = Sawyer | first4 = Jeffery F. | journal = Inorganic Chemistry | volume = 25 | issue = 6 | pages = 777–788 }} In contrast to this tetrachloride, SF4 is a neutral molecule.{{cite journal | doi = 10.1002/anie.201302917 | title = The Solid-State Structure of SF4: The Final Piece of the Puzzle | date = 2013 | last1 = Goettel | first1 = James T. | last2 = Kostiuk | first2 = Nathan | last3 = Gerken | first3 = Michael | journal = Angewandte Chemie International Edition | volume = 52 | issue = 31 | pages = 8037–8040 | pmid = 23784951 }}
Reactions
It decomposes above −30 °C (242 K) to sulfur dichloride and chlorine.
:{{chem2 | SCl4 -> SCl2 + Cl2 }}
It hydrolyzes readily:
:{{chem2 | SCl4 + H2O -> SOCl2 + 2 HCl }}
Sulfur tetrachloride reacts with water, producing hydrogen chloride and sulfur dioxide through the hydrolysis process. Thionyl chloride is an implied intermediate.Holleman-Wiberg, Lehrbuch der Anorganischen Chemie, 101. Auflage, de Gruyter Verlag 1995 {{ISBN|3-11-012641-9}} {{in lang|de}}
:{{chem2 | SCl4 + 2 H2O -> SO2 + 4 HCl }}
It can be oxidized by nitric acid:
:{{chem2 | SCl4 + 2 HNO3 + 2 H2O -> H2SO4 + 2 NO2↑ + 4 HCl }}
References
{{reflist}}
{{sulfur compounds}}
{{Chlorides}}