chemistry

Thiophosphoryl chloride

Thiophosphoryl chloride is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Thiophosphoryl chloride rather than just read about it. In short: Thiophosphoryl chloride is an inorganic compound with the chemical formula PSCl3. It is a colorless pungent smelling liquid that fumes in air.

Key takeaways

Thiophosphoryl chloride belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Thiophosphoryl chloride to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Thiophosphoryl chloride from memory before moving on to harder problems.

Reference excerpt

Thiophosphoryl chloride is an inorganic compound with the chemical formula PSCl3. 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.

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.

3 PCl5 + P2S5 → 5 PSCl3

Structure 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°.

Reactions 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 PSCl3 reacts, and contingent on the reaction conditions, produces either phosphoric acid, hydrogen sulfide, and hydrochloric acid or dichlorothiophosphoric acid and hydrochloric acid.

PSCl3 + 4 H2O → H3PO4 + H2S + 3 HCl PSCl3 + H2O → HO−P(=S)Cl2 + HCl An intermediate in this process appears to be tetraphosphorus nonasulfide. 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, PSCl3 is used to produce insecticides, like parathion.

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. 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.

References

Illustrations

Worked examples

Example 1 — a first encounter with Thiophosphoryl chloride

Start with the simplest possible case. Write down what Thiophosphoryl chloride claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Thiophosphoryl chloride before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Thiophosphoryl chloride ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Thiophosphoryl chloride

In research: Thiophosphoryl chloride appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Thiophosphoryl chloride in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Thiophosphoryl chloride is common in secondary-school and first-year university syllabi. It links to neighbouring topics Phosphorus halides, Thiochlorides, Thiophosphoryl compounds, so understanding it makes those chapters shorter.
In everyday life: Look for Thiophosphoryl chloride outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Thiophosphoryl chloride” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Thiophosphoryl chloride in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Thiophosphoryl chloride means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Thiophosphoryl chloride out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Thiophosphoryl chloride in simple terms?

Thiophosphoryl chloride is an inorganic compound with the chemical formula PSCl3. It is a colorless pungent smelling liquid that fumes in air.

Why does Thiophosphoryl chloride matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Thiophosphoryl chloride?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Thiophosphoryl chloride.