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Thiophosphoryl chloride

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Thiophosphoryl chloride
Structural formula of thiophosphoryl chloride
Ball-and-stick model of thiophosphoryl chloride
Ball-and-stick model of thiophosphoryl chloride
Space-filling model of thiophosphoryl chloride
Space-filling model of thiophosphoryl chloride
Names
IUPAC name
Phosphorothioic trichloride
Other names
  • Phosphoric sulfochloride (1:3)[1]
  • Phosphorus(V) sulfochloride
  • Thiophosphoryl chloride
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.021.476 Edit this at Wikidata
EC Number
  • 223-622-6
RTECS number
  • XN2930000
UNII
UN number 1837
  • InChI=1S/Cl3PS/c1-4(2,3)5 checkY
    Key: WQYSXVGEZYESBR-UHFFFAOYSA-N checkY
  • InChI=1/Cl3PS/c1-4(2,3)5
    Key: WQYSXVGEZYESBR-UHFFFAOYAE
  • P(=S)(Cl)(Cl)Cl
Properties
PSCl3
Molar mass 169.38 g·mol−1
Appearance Colorless liquid
Density 1.67 g/cm3
Melting point −35 °C (−31 °F; 238 K)
Boiling point 125 °C (257 °F; 398 K)
Reacts
Solubility Soluble in benzene, chloroform, CS2 and CCl4.
Structure
Tetrahedral at the P atom
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Violent hydrolysis; releasing HCl on contact with water,[2] maybe corrosive to metals and skin
GHS labelling:[4]
GHS05: CorrosiveGHS06: ToxicGHS07: Exclamation mark
Danger
H302, H314, H330
P260, P264, P270, P271, P280, P284, P301+P317, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P316, P320, P321, P330, P363, P403+P233, P405, P501
Flash point none[3]
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Thiophosphoryl chloride is an inorganic compound with the chemical formula PSCl3.[5] It is a colorless pungent smelling liquid that fumes in air. It is synthesized from phosphorus chloride and used to thiophosphorylate organic compounds, such as to produce insecticides.

Synthesis

[edit]

Thiophosphoryl chloride can be generated by several reactions starting from phosphorus trichloride. The most common and practical synthesis, hence used in industrial manufacturing, is directly reacting phosphorus trichloride with excess sulfur at 180 °C.[6]

PCl3 + S → PSCl3

Using this method, yields can be very high after purification by distillation. Catalysts facilitate the reaction at lower temperatures, but are not usually necessary. Alternatively, it is obtained by combining phosphorus pentasulfide and phosphorus pentachloride.[7]

3 PCl5 + P2S5 → 5 PSCl3

Structure

[edit]

Thiophosphoryl chloride has tetrahedral molecular geometry and C3v molecular symmetry, with the structure S=PCl3. According to gas electron diffraction, the phosphorus–sulfur bond length is 189 pm and the phosphorus–chlorine bond length is 201 pm, while the Cl−P−Cl bond angle is 102°.[8]

Reactions

[edit]

PSCl3 is soluble in benzene, carbon tetrachloride, chloroform, and carbon disulfide.[5] However, it hydrolyzes rapidly in basic or hydroxylic solutions, such as alcohols and amines, to produce thiophosphates.[6] In water PSCl3 reacts, and contingent on the reaction conditions, produces either phosphoric acid, hydrogen sulfide, and hydrochloric acid or dichlorothiophosphoric acid and hydrochloric acid.[9]

PSCl3 + 4 H2O → H3PO4 + H2S + 3 HCl
PSCl3 + H2O → HO−P(=S)Cl2 + HCl

PSCl3 is used to thiophosphorylate organic compounds (to add thiophosphoryl group, P=S, with three free valences at the P atom, to organic compounds).[6] This conversion is widely applicable for amines and alcohols, as well as aminoalcohols, diols, and diamines.[5] Industrially, PSCl3 is used to produce insecticides, like parathion.[9]

PSCl3 + 2 CH3CH2OH → (CH3CH2−O−)2P(=S)−Cl + 2 HCl
(CH3CH2−O−)2P(=S)−Cl + Na+[O−C6H4−NO2] → (CH3CH2−O−)2P(=S)−O−C6H4−NO2 + NaCl

PSCl3 reacts with tertiary amides to generate thioamides.[5] For example:

C6H5−C(=O)−N(−CH3)2 + PSCl3 → C6H5−C(=S)−N(−CH3)2 + POCl3

When treated with methylmagnesium iodide, it give tetramethyldiphosphine disulfide (H3C−)2P(=S)−P(=S)(−CH3)2.[10]

References

[edit]
  1. ^ Thiophosphoryl chloride: trade names
  2. ^ Thiophosphoryl chloride: main hazards
  3. ^ Thiophosphoryl chloride: flash point
  4. ^ "Thiophosphoryl chloride". pubchem.ncbi.nlm.nih.gov.
  5. ^ a b c d Spilling, C. D. "Thiophosphoryl Chloride" in Encyclopedia of Reagents for Organic Synthesis John Wiley & Sons, Weinheim, 2001 doi:10.1002/047084289X.rt104. Article Online Posting Date: April 15, 2001
  6. ^ a b c Betterman G, Krause W, Riess G, Hofmann T (2005). "Phosphorus Compounds, Inorganic". Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_527. ISBN 3527306730.
  7. ^ Martin, D. R.; Duvall, W. M. “Phosphorus(V) Sulfochloride” Inorganic Syntheses, 1953, Volume IV, p73. doi:10.1002/9780470132357.ch24.
  8. ^ Kuchitsu, Kozo; Moritani, Tohei; Morino, Yonezo (1971). "Molecular structures of phosphoryl fluoride, phosphoryl chloride, and thiophosphoryl chloride studied by gas electron diffraction". Inorganic Chemistry. 10 (2): 344–350. doi:10.1021/ic50096a025.
  9. ^ a b Fee, D. C.; Gard, D. R.; Yang, C. “Phosphorus Compounds” Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons: New York, 2005 doi:10.1002/0471238961.16081519060505.a01.pub2
  10. ^ G. W. Parshall "Tetramethylbiphosphine Disulfide" Org. Synth. 1965, volume 45, p. 102. doi:10.15227/orgsyn.045.0102