15. Analytical Techniques:IR, NMR, Mass Spect

For the molecules in Assessment 15.58, give an approximate chemical shift for each indicated carbon. [The range of correct answers is large here.].

(c)

Draw the ¹³C NMR spectrum of each molecule in Assessment 15.48.

(a)

Draw the ¹³C NMR spectrum of each molecule in Assessment 15.48.

(b)

Draw the ¹³C NMR spectrum of each molecule in Assessment 15.48.

(c)

How many signals would you expect in the ¹³C NMR spectrum of each molecule shown?

(b)

How many signals would you expect in the ¹³C NMR spectrum of each molecule shown?

(c)

Assign each signal in the ¹³C NMR spectra to the molecule shown.

(b) <IMAGE>

Draw the ¹³C NMR spectrum you would expect to see for each of the molecules shown.

(a)

Draw the ¹³C NMR spectrum you would expect to see for each of the molecules shown.

(b)

Draw the ¹³C NMR spectrum you would expect to see for each of the molecules shown.

(c)

How might you use ¹³C NMR spectroscopy to differentiate between the possible ortho, meta, and para products of the electrophilic aromatic substitution reaction shown?

Sketch the following spectra that would be obtained for 2-chloroethanol:

e. The four parts of a DEPT ¹³C NMR spectrum.

Identify the compound with molecular formula C₆H₁₀O that gives the following DEPT ¹³C NMR spectrum:

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The standard ¹³C NMR spectrum of phenyl propanoate is shown here. Predict the appearance of the DEPT-90 and DEPT-135 spectra.

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Different types of protons and carbons in alkanes tend to absorb at similar chemical shifts, making structure determination difficult. Explain how the ¹³C NMR spectrum, including the DEPT technique, would allow you to distinguish among the following four isomers.