chemistry

Samarium(II) bromide

Samarium(II) bromide 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 Samarium(II) bromide rather than just read about it. In short: Samarium(II) bromide is an inorganic compound with the chemical formula SmBr2. It is a brown solid that is insoluble in most solvents but degrades readily in air.

Key takeaways

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

Reference excerpt

Samarium(II) bromide is an inorganic compound with the chemical formula SmBr2. It is a brown solid that is insoluble in most solvents but degrades readily in air.

Structure In the gas phase, SmBr2 is a bent molecule with Sm–Br distance 274.5 pm and bond angle 131±6°.

History Samarium(II) bromide was first synthesized in 1934 by P. W. Selwood, when he reduced samarium tribromide (SmBr3) with hydrogen (H2). Kagan also synthesized it by converting samarium(III) oxide (Sm2O3) to SmBr3 and then reducing with a lithium dispersion in THF. Robert A. Flowers synthesized it by adding two equivalent of lithium bromide (LiBr) to samarium diiodide (SmI2) in tetrahydrofuran. Namy managed to synthesize it by mixing tetrabromoethane (C2H2Br4) with samarium metal, and Hilmerson found that heating the tetrabromoethane or samarium greatly improved the production of samarium(II) bromide.

Reactions Samarium(II) bromide has reducing properties reminiscent of the more commonly used samarium diiodide. It is an effective for pinacol homocouplings of aldehydes, ketones, and cross-coupling carbonyl compounds. Reports have shown that samarium(II) bromide is capable of selectively reducing ketones if it is in the presence of an alkyl halide. Samarium(II) bromide forms soluble adducts with hexamethylphosphoramide. This species reduces imines to amines and alkyl chlorides to hydrocarbons. For example, SmBr2(hmpa)x converts cyclohexyl chloride to cyclohexane. Samarium(II) bromide will reduce ketones in tetrahydrofuran if an activator is absent.

References

Illustrations

Worked examples

Example 1 — a first encounter with Samarium(II) bromide

Start with the simplest possible case. Write down what Samarium(II) bromide 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 Samarium(II) 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 Samarium(II) 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 Samarium(II) bromide

In research: Samarium(II) bromide 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 Samarium(II) 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: Samarium(II) bromide is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bromides, Lanthanide halides, Reducing agents, so understanding it makes those chapters shorter.
In everyday life: Look for Samarium(II) 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 Samarium(II) bromide in 20 minutes

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

Frequently asked questions

What is Samarium(II) bromide in simple terms?

Samarium(II) bromide is an inorganic compound with the chemical formula SmBr2. It is a brown solid that is insoluble in most solvents but degrades readily in air.

Why does Samarium(II) bromide 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 Samarium(II) 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 Samarium(II) bromide.