science

Tetraethylammonium bromide

Tetraethylammonium bromide is a science 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 Tetraethylammonium bromide rather than just read about it. In short: Tetraethylammonium bromide (TEAB) is a quaternary ammonium compound with the chemical formula C8H20N+Br−, often written as "Et4N+Br−" in the chemical literature. It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis.

Key takeaways

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

Reference excerpt

Tetraethylammonium bromide (TEAB) is a quaternary ammonium compound with the chemical formula C8H20N+Br−, often written as "Et4N+Br−" in the chemical literature. It has been used as the source of tetraethylammonium ions in pharmacological and physiological studies, but is also used in organic chemical synthesis.

Chemistry

Synthesis TEAB is commercially available, but can be prepared by the reaction between tetraethylammonium hydroxide and hydrobromic acid:

Et4N+HO− + HBr → Et4N+Br− + H2O Evaporation of the water and recrystallization from acetonitrile yields a crystalline sample of TEAB.

Structure The crystal structure of TEAB has been determined and found to exhibit a distorted tetrahedral symmetry with respect to the geometry of the C atoms around the central N.

Synthetic applications Examples include:

TEAB catalyzes the high-yield oxidation of organic sulfides to sulfoxides by o-iodoxybenzoic acid (IBX) in chloroform/water at room temperature, e.g. (C2H5)2S → (C2H5)2S=O TEAB has been used for the in situ preparation of tetraethylammonium superoxide from potassium superoxide for the conversion of primary alkyl halides to dialkyl peroxides. The overall reaction is: 2R1Br + 2KO2 → R1-O-O-R1 + 2KBr + O2

Biology In common with tetraethylammonium chloride and tetraethylammonium iodide, TEAB has been used as a source of tetraethylammonium ions for numerous clinical and pharmacological studies, which are covered in more detail under the entry for tetraethylammonium. Briefly, TEAB has been explored clinically for its ganglionic blocking properties, although it is now essentially obsolete as a drug, and it is still used in physiological research for its ability to block K+ channels in various tissues.

Toxicity The toxicity of TEAB is primarily due to the tetraethylammonium ion, which has been studied extensively. The acute toxicity of TEAB is comparable to that of tetraethylammonium chloride and tetraethylammonium iodide. These data, taken from a study by Randall and co-workers, are provided for comparative purposes; additional details may be found in the entry for Tetraethylammonium. LD50 for mouse: 38 mg/kg, i.v.; 60 mg/kg, i.p.; >2000 mg/kg, p.o.

See also Tetraethylammonium Tetraethylammonium chloride Tetraethylammonium iodide

References

Illustrations

Worked examples

Example 1 — a first encounter with Tetraethylammonium bromide

Start with the simplest possible case. Write down what Tetraethylammonium bromide claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Tetraethylammonium bromide 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 Tetraethylammonium bromide 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 Tetraethylammonium bromide

In research: Tetraethylammonium bromide appears in science 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 Tetraethylammonium bromide 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: Tetraethylammonium bromide is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bromides, Tetraethylammonium salts, so understanding it makes those chapters shorter.
In everyday life: Look for Tetraethylammonium bromide 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 Tetraethylammonium bromide in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tetraethylammonium bromide 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 Tetraethylammonium bromide out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tetraethylammonium bromide in simple terms?

Why does Tetraethylammonium bromide matter?

Because it connects several science 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 Tetraethylammonium bromide?

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 Tetraethylammonium bromide.