15. Analytical Techniques:IR, NMR, Mass Spect

Predict the splitting patterns for the signals given by the compounds in Problem 4.

j.

Label each set of chemically equivalent protons, using a for the set that will be at the lowest frequency in the ¹H NMR spectrum, b for the next lowest, and so on. Indicate the multiplicity of each signal.

c.

Draw all of the possible spin states to explain why a hydrogen with four neighbors appears as a quintet (quint, five peaks).

Predict the splitting pattern (multiplicity) for the following molecule:

Predict the splitting pattern (multiplicity) for the following molecule:

Indicate the number of signals and the multiplicity of each signal in the 1H NMR spectrum of each of the following compounds:

a. CH₃CH₂CH₂CH₂CH₂CH₃

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

d.

Which of the following compounds gives a 1H NMR spectrum consisting of only a singlet, a triplet, and a pentet?

Predict the splitting patterns for the signals given by the compounds in Problem 4.

i.

Predict the multiplicity (the number of peaks as a result of splitting) and the chemical shift for each shaded proton in the following compounds.

(a)

(b)

Predict the splitting patterns for the signals given by the compounds in Problem 4.

c. CH₂=CCl₂

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

b. CH₃OCH₂CH₂CH₂Br

Why is there no coupling between the a and c protons or between the b and c protons in the cis and trans alkenes shown in Figure 14.20?

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In Figure 15.34, H_a was assumed to be 'up.' How does the analysis change if we assume instead that H_a is down?

Predict the splitting pattern for each of the indicated hydrogens in Assessment 15.59.

(a)