Sulfur tetrachloride

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Sulfur tetrachloride
Sulfur tetrachloride.svg
Identifiers
CAS number 13451-08-6
Jmol-3D images Image 1
Properties
Molecular formula SCl4
Molar mass 173.87
Appearance White powder
Melting point -31°C
Boiling point -20°C (decomposes)
Solubility in water soluble in water
Hazards
R-phrases R14, R34, R50
S-phrases (S1/2), S26, S45, S61
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Sulfur tetrachloride is an inorganic compound with chemical formula SCl4. It is an unstable pale yellow solid, decomposing to sulfur dichloride and chlorine at temperatures above 242K. It is obtained by treating sulfur dichlorides with chlorine at 193K:

\rm \ SCl_2 + Cl_2 \xrightarrow{193K} SCl_4

Its solid structure is uncertain. It is probably the salt SCl3+Cl-, since related salts are known.[1]

Characteristics[edit]

Sulfur tetrachloride is stable in solid state below -30 °C, and it decomposes to chlorine and sulfur when temperature rises. In solid state, there is a white, finely powdered substance. It melts with simultaneous decomposition if higher than -20 °C.[2] Sulfur tetrachloride reacts with water, producing hydrogen chloride and sulfur dioxide through the hydrolysis process.[3]

Gas phase SCl4 has a seesaw molecular geometry as evidenced from microwave spectroscopy and electron diffraction.[4] The liquid has a fluxional trigonal bipyramidal geometry with rapid exchange of the axial and equatorial fluorine atoms on the NMR timescale at room temperature.[4] For the solid state a structure has been reported consisting of a SCl4 seesaw geometry [4] linked in a three-dimensional network by weak S-F interactions, two per molecule.

Reactions[edit]

  • Decomposition:
\mathrm{SCl_4 \ \xrightarrow{-15^oC}\ SCl_2 + Cl_2 }
  • Reacting with water in air:
\mathrm{SCl_4 + H_2O \ \xrightarrow{}\ SOCl_2 + 2HCl }
  • Treated with water:
\mathrm{SCl_4 + 2H_2O \ \xrightarrow{}\ SO_2 + 4HCl }
\mathrm{SCl_4 + 2HNO_3 + 2H_2O \ \xrightarrow{}\ H_2SO_4 + 2NO_2\uparrow + 4HCl }
\mathrm{SCl_4 + 6NaOH \ \xrightarrow{}\ Na_2SO_3 + 4NaCl + 3H_2O }[5][6][7]

References[edit]

  1. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419. 
  2. ^ Georg Brauer: Handbuch der Präparativen Anorganischen Chemie. (German)
  3. ^ Holleman-Wiberg, Lehrbuch der Anorganischen Chemie, 101. Auflage, de Gruyter Verlag 1995 ISBN 3-11-012641-9 (German)
  4. ^ a b c Goettel, J. T., Kostiuk, N. and Gerken, M. (2013), The Solid-State Structure of SF4: The Final Piece of the Puzzle . Angew. Chem. Int. Ed., 52: 8037–8040. doi:10.1002/anie.201302917
  5. ^ Справочник химика / Редкол.: Никольский Б.П. и др.. — 3-е изд., испр. — Л.: Химия, 1971. — Т. 2. — 1168 с. (Russian)
  6. ^ Химическая энциклопедия / Редкол.: Кнунянц И.Л. и др.. — М.: Советская энциклопедия, 1995. — Т. 4. — 639 с. — ISBN 5-82270-092-4 (Russian)
  7. ^ Лидин Р.А. и др. Химические свойства неорганических веществ: Учеб. пособие для вузов. — 3-е изд., испр. — М.: Химия, 2000. — 480 с. — ISBN 5-7245-1163-0 (Russian)