Logout Open In App
Open In App
Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Chapter 13: Q.33P (page 701)

Question: An unknown compound has the molecular formula C9H11Br. Its proton NMR spectrum shows the following absorptions: singlet, d7.1, integral 44 mm singlet, d2.3, integral 130 mm singlet, d2.2, integral 67 mm Propose a structure for this compound.

Short Answer

Expert verified

Answer

The unknown compound is 2 bromo-1,3,5,trimehylbenzene

Step by step solution

01

Introduction to NMR spectroscopy

Proton magnetic resonance (PMR) is a particular branch of NMR spectroscopy where the nucleus is a proton. NMR and PMR spectroscopies are principally considered to be the same.

02

Explanation

The proton NMR spectrum for the unknown compound has the molecular formula C9H11Br and can be drawn as shown below:

Hence, the compound with the molecular formula C9H11Br is 2 bromo-1,3,5,trimehylbenzene .

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A new chemist moved into an industrial lab where work was being done on oxygenated gasoline additives. Among the additives that had been tested, she found an old bottle containing a clear, pleasant-smelling liquid that was missing its label. She took the quick NMR spectrum shown and was able to determine the identity of the compound without any additional information. Propose a structure and assign the peaks. (Hint: This is a very pure sample.)

A bottle of allyl bromide was found to contain a large amount of an impurity. A careful distillation separated the impurity, which has the molecular formula C3H60. The following 13CNMR spectrum of the impurity was obtained:

  1. Propose a structure for this impurity.
  2. Assign the peaks in the13CNMR spectrum to the carbon atoms in the structure.
  3. Suggest how this impurity arose in the allyl bromide sample.

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

The following spectra are taken from a compound that is an important starting material for organic synthesis. Determine the structure, first by considering each spectrum individually, and then by considering all the spectra together. Assign peaks to show that your proposed structure accounts for all the major features of each spectrum. DEPT information is given in blue on the carbon NMR.

Question: How many signals would you expect to see in the 13CNMR of the following compounds? In each case, show which carbon atoms are equivalent in the 13CNMR.
See all solutions

Recommended explanations on Chemistry Textbooks

Chemical Reactions

Read Explanation

Chemical Analysis

Read Explanation

Nuclear Chemistry

Read Explanation

Chemistry Branches

Read Explanation

Inorganic Chemistry

Read Explanation

Kinetics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free