15. Analytical Techniques:IR, NMR, Mass Spect

The ¹H NMR spectra of three isomers with molecular formula C₄H₉Br are shown here. Which isomer produces which spectrum?

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The ¹H NMR spectra of three isomers with molecular formula C₄H₉Br are shown here. Which isomer produces which spectrum?

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The ¹H NMR spectra of three isomers with molecular formula C₄H₉Br are shown here. Which isomer produces which spectrum?

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Match each of the ¹H NMR spectra with one of the following compounds:

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Propose structures that are consistent with the following spectra. (Integral ratios are given from left to right across the spectrum.)

b. The ¹H NMR spectrum of a compound with molecular formula C₆H₁₀O₂ has two singlets with integral ratios of 2 : 3.

Which of the following compounds is responsible for the ¹H NMR spectrum shown below?

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Identify each compound from its molecular formula and its ¹H NMR spectrum:

b. C₅H₁₀O

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Describe the ¹H NMR spectrum you would expect for each of the following compounds, indicating the relative positions of the signals:

n.

The following ¹H NMR spectra are for four compounds, each with molecular formula of C₆H₁₂O₂. Identify the compounds.

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When compound A (C₅H₁₂O) is treated with HBr, it forms compound B (C₅H₁₁Br). The ¹H NMR spectrum of compound A has a 1H singlet, a 3H doublet, a 6H doublet, and two 1H multiplets. The ¹H NMR spectrum of compound B has a 6H singlet, a 3H triplet, and a 2H quartet. Identify compounds A and B.

Identify each of the following compounds from its molecular formula and its IR and ¹H NMR spectra:

d. C₁₁H₁₄O₂

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In the lab, ¹H NMR is often used to verify that a reaction has worked as expected by comparing the product spectrum with what is expected. Given the ¹H NMR of the reactant shown, draw the spectrum you'd expect to see of the product that results.

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(a) Using the ¹H NMR spectra, identify the reactants and product for this reaction.

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(b) Provide an arrow-pushing mechanism for the reaction.

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Without worrying about the relative location of the signals (i.e., the chemical shift) or the splitting patterns, draw a spectrum of the following molecule, being sure to indicate the integration of each peak. Label each signal based on the set of equivalent hydrogens to which it corresponds. [We expand on this question in future assessments.]