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Thiophosphoryl chloride
Ball-and-stick model of thiophosphoryl chloride	Space-filling model of thiophosphoryl chloride
Names
	IUPAC name Phosphorothioic trichloride
	Other names Phosphoric sulfochloride (1:3); Phosphorus(V) sulfochloride; Thiophosphoryl chloride;
Identifiers
CAS Number	3982-91-0 ;
3D model (JSmol)	Interactive image;
ChemSpider	18729 ;
ECHA InfoCard	100.021.476
EC Number	223-622-6;
PubChem CID	19883;
RTECS number	XN2930000;
UNII	II99F8594N ;
UN number	1837
CompTox Dashboard (EPA)	DTXSID3063253 ;
	InChI InChI=1S/Cl3PS/c1-4(2,3)5 Key: WQYSXVGEZYESBR-UHFFFAOYSA-N ; InChI=1/Cl3PS/c1-4(2,3)5 Key: WQYSXVGEZYESBR-UHFFFAOYAE;
	SMILES P(=S)(Cl)(Cl)Cl;
Properties
Chemical formula	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)
Solubility in water	Reacts
Solubility	Soluble in benzene, chloroform, CS2 and CCl4.
Structure
Molecular shape	Tetrahedral at the P atom
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Violent hydrolysis; releasing HCl on contact with water, maybe corrosive to metals and skin
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H314, H330
Precautionary statements	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
Related compounds
Related compounds	Phosphoryl chloride; Thiophosphoryl fluoride; Thiophosphoryl bromide; Thiophosphoryl iodide; Phosphorothioic chloride difluoride;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Thiophosphoryl chloride is an inorganic compound with the chemical formula P S Cl₃.^[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

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

Thiophosphoryl chloride has tetrahedral molecular geometry and C_3v 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

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

An intermediate in this process appears to be tetraphosphorus nonasulfide.^[10]

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.^[11]

References

^ Thiophosphoryl chloride: trade names
^ Thiophosphoryl chloride: main hazards
^ Thiophosphoryl chloride: flash point
^ "Thiophosphoryl chloride". pubchem.ncbi.nlm.nih.gov.
^ ^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
^ ^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.
^ Martin, D. R.; Duvall, W. M. “Phosphorus(V) Sulfochloride” Inorganic Syntheses, 1953, Volume IV, p73. doi:10.1002/9780470132357.ch24.
^ 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.
^ ^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
^ Almasi, Lucreţia (1971). "The Sulfur–Phosphorus Bond". In Senning, Alexander (ed.). Sulfur in Organic and Inorganic Chemistry. Vol. 1. New York: Marcel Dekker. p. 69. ISBN 0-8247-1615-9. LCCN 70-154612.
^ G. W. Parshall "Tetramethylbiphosphine Disulfide" Org. Synth. 1965, volume 45, p. 102. doi:10.15227/orgsyn.045.0102