Skip to main content
Ch. 15 - Structural Identification II: Nuclear Magnetic Resonance Spectroscopy
Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
Chapter 14, Problem 63d

Complete the table of ¹H NMR data you'd generate for each of the following molecules.
(d) Structural formula of 1-chloropentane, showing a five-carbon chain with a chlorine atom attached to the terminal carbon.

Verified step by step guidance
1
Identify the structure of the molecule in question. Determine the number of unique hydrogen environments present in the molecule. Each unique environment will correspond to a different signal in the ¹H NMR spectrum.
For each unique hydrogen environment, determine the chemical shift range. Chemical shifts are influenced by the electronic environment surrounding the hydrogen atoms. Consider factors such as electronegativity of nearby atoms, hybridization, and aromaticity.
Determine the splitting pattern for each signal. The splitting pattern is determined by the number of neighboring hydrogen atoms (n) using the n+1 rule, where n is the number of adjacent hydrogens.
Estimate the integration of each signal. The integration corresponds to the number of hydrogen atoms contributing to each signal. This is typically represented as a ratio in the NMR spectrum.
Compile the data into a table format, listing each unique hydrogen environment, its chemical shift, splitting pattern, and integration. This will provide a comprehensive overview of the ¹H NMR data for the molecule.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
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 technique used to determine the structure of organic compounds by analyzing the magnetic environment of hydrogen atoms. It provides information about the number of hydrogen atoms, their chemical environment, and how they are connected within a molecule. The resulting spectrum displays peaks corresponding to different hydrogen environments, which can be interpreted to deduce structural information.
Recommended video:
Guided course
10:06
General NMR Features

Chemical Shift

Chemical shift in ¹H NMR refers to the position of the NMR signal relative to a standard reference compound, usually tetramethylsilane (TMS). It is measured in parts per million (ppm) and indicates the electronic environment surrounding a hydrogen atom. Factors such as electronegativity of nearby atoms and hybridization affect the chemical shift, helping to identify functional groups and structural features in a molecule.
Recommended video:
Guided course
11:44
1H NMR Chemical Shifts

Spin-Spin Coupling

Spin-spin coupling, also known as J-coupling, occurs when non-equivalent hydrogen atoms influence each other's magnetic environment, causing splitting of NMR signals into multiplets. The pattern and number of peaks in a multiplet provide information about the number of neighboring hydrogen atoms (n+1 rule) and their spatial relationship. This coupling helps elucidate the connectivity and arrangement of atoms within a molecule.
Recommended video:
Guided course
02:54
Sonogashira Coupling Reaction