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chemistry

Triethyl phosphite

Triethyl phosphite 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 Triethyl phosphite rather than just read about it. In short: Triethyl phosphite (TEP) is an organophosphorus compound, specifically a phosphite ester, with the formula P(OCH2CH3)3, often abbreviated P(OEt)3. It is a colorless, malodorous liquid.

Triethyl phosphite — main illustration
Triethyl phosphite — illustration

Key takeaways

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

Reference excerpt

Triethyl phosphite (TEP) is an organophosphorus compound, specifically a phosphite ester, with the formula P(OCH2CH3)3, often abbreviated P(OEt)3. It is a colorless, malodorous liquid. It is used as a ligand in organometallic chemistry and as a reagent in organic synthesis. The molecule features a pyramidal phosphorus(III) center bound to three ethoxide groups. Its 31P NMR spectrum features a signal at around +139 ppm vs phosphoric acid standard. Triethylphosphite is prepared by treating phosphorus trichloride with ethanol in the presence of a base, typically a tertiary amine:

PCl3 + 3 EtOH + 3 R3N → P(OEt)3 + 3 R3NH + 3 Cl− In the absence of the base, the reaction of ethanol and phosphorus trichloride affords diethylphosphite ((EtO)2P(O)H). Of the many related compounds can be prepared similarly, triisopropyl phosphite is an example (b.p. 43.5 °C/1.0 mm; CAS# 116-17-6).

Reactions Triethyl phosphite can react with electrophiles in a Michaelis–Arbuzov reaction to produce organophosphonates. For example, the reaction between triethyl phosphite and ethyl bromoacetate produces a phosphonate suitable for use in the Horner–Wadsworth–Emmons reaction.

Reduction/deoxygenation of hydroperoxides to the alcohols can also be effected using triethyl phosphite. This approach can be utilized for carbonyl α-hydroxylation by reacting the enolate with oxygen, producing an α-hydroperoxide which can be reduced by triethyl phosphite to the alcohol. A proposed mechanism is shown below.

Triethyl phosphite can also be used in the Corey–Winter olefin synthesis.

As a ligand In coordination chemistry and homogeneous catalysis, triethylphosphite finds use as a soft ligand. Its complexes are generally lipophilic and feature metals in low oxidation states. Examples include the colorless complexes FeH2(P(OEt)3)4 and Ni(P(OEt)3)4 (m.p. 108 °C). It also forms a stable complex with copper(I) iodide.

References

External links Eastman triethyl phosphate (TEP) WebBook page for C6H15PO3

Illustrations

Triethyl phosphite illustration
Triethyl phosphite illustration
Triethyl phosphite: Michaelis–Arbuzov reaction between ethyl bromoacetate and triethyl phosphite resulting in an organophosphonate.
Michaelis–Arbuzov reaction between ethyl bromoacetate and triethyl phosphite resulting in an organophosphonate.
Triethyl phosphite: Reaction scheme and proposed mechanism for carbonyl α-hydroxylation using oxygen and triethyl phosphite.
Reaction scheme and proposed mechanism for carbonyl α-hydroxylation using oxygen and triethyl phosphite.

Worked examples

Example 1 — a first encounter with Triethyl phosphite

Start with the simplest possible case. Write down what Triethyl phosphite 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 Triethyl phosphite 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 Triethyl phosphite 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 Triethyl phosphite

In research
Triethyl phosphite 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 Triethyl phosphite 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
Triethyl phosphite is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ethyl esters, Foul-smelling chemicals, Organophosphites, so understanding it makes those chapters shorter.
In everyday life
Look for Triethyl phosphite 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.

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How to study Triethyl phosphite in 20 minutes

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

Frequently asked questions

What is Triethyl phosphite in simple terms?

Triethyl phosphite (TEP) is an organophosphorus compound, specifically a phosphite ester, with the formula P(OCH2CH3)3, often abbreviated P(OEt)3. It is a colorless, malodorous liquid.

Why does Triethyl phosphite 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 Triethyl phosphite?

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 Triethyl phosphite.

Tags

  • Ethyl esters
  • Foul-smelling chemicals
  • Organophosphites

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