Skip to main content
Ch. 14 - NMR Spectroscopy
Bruice - Organic Chemistry 8th Edition
Bruice8th EditionOrganic ChemistryISBN: 9780135213711Not the one you use?Change textbook
All textbooksBruice 8th EditionCh. 14 - NMR SpectroscopyProblem 18
Chapter 15, Problem 18

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

<IMAGE>

Verified step by step guidance
1
Analyze the given 1H NMR spectrum to identify the number of signals. Each signal corresponds to a unique set of chemically equivalent protons in the molecule.
Examine the splitting pattern (multiplicity) of each signal. The splitting pattern (singlet, doublet, triplet, etc.) provides information about the number of neighboring protons (n+1 rule).
Determine the chemical shift (in ppm) of each signal. The chemical shift indicates the electronic environment of the protons, helping to identify functional groups or structural features.
Integrate the signals to find the relative number of protons contributing to each signal. This helps in determining the ratio of different types of protons in the molecule.
Compare the information from the NMR spectrum (number of signals, splitting patterns, chemical shifts, and integration) with the possible structures of the compounds provided. Match the data to the compound that fits all the observed characteristics.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

1H NMR Spectroscopy

1H NMR (Proton Nuclear Magnetic Resonance) spectroscopy is a powerful analytical technique used to determine the structure of organic compounds. It provides information about the number of hydrogen atoms in different environments within a molecule, allowing chemists to infer connectivity and functional groups. The chemical shifts, splitting patterns, and integration of peaks in the spectrum are key to interpreting the molecular structure.
Recommended video:
Guided course
06:46
1H NMR Integration

Chemical Shift

Chemical shift refers to the resonance frequency of a nucleus relative to a standard in a magnetic field, typically measured in parts per million (ppm). In 1H NMR, different hydrogen atoms resonate at different frequencies based on their electronic environment, influenced by nearby electronegative atoms or functional groups. Understanding chemical shifts helps in identifying the types of hydrogen present in a compound.
Recommended video:
Guided course
11:44
1H NMR Chemical Shifts

Integration and Splitting Patterns

Integration in 1H NMR spectroscopy indicates the relative number of hydrogen atoms contributing to a particular signal, while splitting patterns reveal the number of neighboring hydrogen atoms (n+1 rule). This information helps deduce the connectivity and arrangement of atoms in a molecule. Analyzing these patterns is crucial for accurately determining the structure of the compound responsible for the observed spectrum.
Recommended video:
Guided course
08:06
Common Splitting Patterns
Related Practice
Textbook Question

[18]-Annulene shows two signals in its 1H NMR spectrum: one at 9.25 ppm and the other to the right of the TMS signal at –2.88 ppm. What hydrogens are responsible for each of the signals? (Hint: Look at the direction of the induced magnetic field outside and inside the benzene ring in Figure 14.6.)

1
views
Textbook Question

Draw a diagram like the one shown in Figure 14.12 to predict

b. the relative intensities of the peaks in a quintet.

<IMAGE>

2
views
Textbook Question

Draw a diagram like the one shown in Figure 14.12 to predict

a. the relative intensities of the peaks in a triplet.

<IMAGE>

2
views
Textbook Question

How would integration distinguish the 1H NMR spectra of the following compounds?

2
views
Textbook Question

Without referring to Table 14.1, label the proton or set of protons in each compound that gives the signal at the lowest frequency a, at the next lowest b, and so on.

h.

1
views
Textbook Question

Explain how the following compounds, each with the same molecular formula, could be distinguished by their 1H NMR spectra.

1
views