Thiophosphoryl chloride

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.{{cite encyclopedia |vauthors=Betterman G, Krause W, Riess G, Hofmann T|title=Phosphorus Compounds, Inorganic |encyclopedia=Ullmann’s Encyclopedia of Industrial Chemistry|year=2005|publisher=Wiley-VCH |location=Weinheim |isbn=3527306730 |doi=10.1002/14356007.a19_527}}

:{{chem2|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.Martin, D. R.; Duvall, W. M. “Phosphorus(V) Sulfochloride” Inorganic Syntheses, 1953, Volume IV, p73. {{doi| 10.1002/9780470132357.ch24}}.

:{{chem2|3 PCl5 + P2S5 → 5 PSCl3}}

Thiophosphoryl chloride has tetrahedral molecular geometry and C_3v molecular symmetry, with the structure {{chem2|S\dPCl3}}. According to gas electron diffraction, the phosphorus–sulfur bond length is 189 pm and the phosphorus–chlorine bond length is 201 pm, while the {{chem2|Cl\sP\sCl}} bond angle is 102°.{{cite journal | title = Molecular structures of phosphoryl fluoride, phosphoryl chloride, and thiophosphoryl chloride studied by gas electron diffraction | first1 = Kozo | last1 = Kuchitsu | first2 = Tohei | last2 = Moritani | first3 = Yonezo | last3 = Morino | journal = Inorganic Chemistry | year = 1971 | volume = 10 | issue = 2 | pages = 344–350 | doi = 10.1021/ic50096a025}}

{{chem2|PSCl3}} is soluble in benzene, carbon tetrachloride, chloroform, and carbon disulfide. However, it hydrolyzes rapidly in basic or hydroxylic solutions, such as alcohols and amines, to produce thiophosphates. In water {{chem2|PSCl3}} reacts, and contingent on the reaction conditions, produces either phosphoric acid, hydrogen sulfide, and hydrochloric acid or dichlorothiophosphoric acid and hydrochloric acid.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}}

:{{chem2|PSCl3 + 4 H2O → H3PO4 + H2S + 3 HCl}}

:{{chem2|PSCl3 + H2O → HO\sP(\dS)Cl2 + HCl}}

An intermediate in this process appears to be tetraphosphorus nonasulfide.{{cite book|title=Sulfur in Organic and Inorganic Chemistry|volume=1|editor-first=Alexander|editor-last=Senning|year=1971|publisher=Marcel Dekker|location=New York|lccn=70-154612|isbn=0-8247-1615-9|first=Lucreţia|last=Almasi|chapter=The Sulfur–Phosphorus Bond|page=69}}

{{chem2|PSCl3}} is used to thiophosphorylate organic compounds (to add thiophosphoryl group, P=S, with three free valences at the P atom, to organic compounds). This conversion is widely applicable for amines and alcohols, as well as aminoalcohols, diols, and diamines. Industrially, {{chem2|PSCl3}} is used to produce insecticides, like parathion.

:{{chem2|PSCl3 + 2 CH3CH2OH → (CH3CH2\sO\s)2P(\dS)\sCl + 2 HCl}}

:{{chem2|(CH3CH2\sO\s)2P(\dS)\sCl + Na+[−O\sC6H4\sNO2] → (CH3CH2\sO\s)2P(\dS)\sO\sC6H4\sNO2 + NaCl}}

{{chem2|PSCl3}} reacts with tertiary amides to generate thioamides. For example:

:{{chem2|C6H5\sC(\dO)\sN(\sCH3)2 + PSCl3 → C6H5\sC(\dS)\sN(\sCH3)2 + POCl3}}

When treated with methylmagnesium iodide, it give tetramethyldiphosphine disulfide {{chem2|(H3C\s)2P(\dS)\sP(\dS)(\sCH3)2}}.G. W. Parshall "Tetramethylbiphosphine Disulfide" Org. Synth. 1965, volume 45, p. 102. {{doi|10.15227/orgsyn.045.0102}}

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Category:Phosphorus halides

Category:Thiophosphoryl compounds

Category:Thiochlorides