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.

Sulfur tetrachloride
Names
IUPAC name
Sulfur(IV) chloride
Identifiers
3D model (JSmol)
ECHA InfoCard 100.149.178 Edit this at Wikidata
  • InChI=1/Cl4S/c1-5(2,3)4
  • ClS(Cl)(Cl)Cl
Properties
SCl4
Molar mass 173.87
Appearance White powder
Melting point −31 °C (−24 °F; 242 K)
Boiling point −20 °C (−4 °F; 253 K) (decomposes)
soluble in water
Hazards
GHS labelling:
GHS05: CorrosiveGHS09: Environmental hazard
Danger
H314, H400
P260, P264, P273, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P391, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Preparation and structure

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It is obtained by treating sulfur dichloride with chlorine at 193 K:

SCl2 + Cl2 → SCl4

It melts with simultaneous decomposition above −20 °C.[1]

Its solid structure is uncertain. It is probably the salt SCl3+Cl, since related salts are known with noncoordinating anions.[2][3] In contrast to this tetrachloride, SF4 is a neutral molecule.[4]

Reactions

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It decomposes above −30 °C (242 K) to sulfur dichloride and chlorine.

SCl4 → SCl2 + Cl2

It hydrolyzes readily:

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.[5]

SCl4 + 2 H2O → SO2 + 4 HCl

It can be oxidized by nitric acid:

SCl4 + 2 HNO3 + 2 H2O → H2SO4 + 2 NO2↑ + 4 HCl

References

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  1. ^ Georg Brauer: Handbuch der Präparativen Anorganischen Chemie. (in German)
  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  3. ^ Christian, Beverly H.; Collins, Michael J.; Gillespie, Ronald J.; Sawyer, Jeffery F. (1986). "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)". Inorganic Chemistry. 25 (6): 777–788. doi:10.1021/ic00226a012.
  4. ^ Goettel, James T.; Kostiuk, Nathan; Gerken, Michael (2013). "The Solid-State Structure of SF4: The Final Piece of the Puzzle". Angewandte Chemie International Edition. 52 (31): 8037–8040. doi:10.1002/anie.201302917. PMID 23784951.
  5. ^ Holleman-Wiberg, Lehrbuch der Anorganischen Chemie, 101. Auflage, de Gruyter Verlag 1995 ISBN 3-11-012641-9 (in German)