Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

15. Analytical Techniques:IR, NMR, Mass Spect

Mass Spect:Fragmentation

Organic Chemistry

15. Analytical Techniques:IR, NMR, Mass Spect

Mass Spect:Fragmentation

Previous problemNext problem

8:09 minutes

Problem 17c

Textbook Question

Using curved arrows, show the principal fragments you would expect to see in the mass spectrum of each of the following compounds:
c.

Verified step by step guidance

Identify the molecular structure of the compound provided in the problem. Analyze its functional groups, bonds, and overall connectivity to determine potential sites for fragmentation during mass spectrometry.

Recall that in mass spectrometry, fragmentation occurs when the molecule is ionized, typically by electron impact, leading to the formation of a molecular ion (M⁺). This ion can then break into smaller fragments. Use curved arrows to represent the movement of electrons during bond cleavage.

Determine the most likely fragmentation pathways by considering the stability of the resulting cations and radicals. For example, cleavage near functional groups such as alcohols, carbonyls, or alkyl groups often leads to stable carbocations or resonance-stabilized ions.

Draw the principal fragments formed during the fragmentation process. Use curved arrows to show the electron movement that leads to the bond breaking and the formation of the fragments. Label the fragments with their respective m/z (mass-to-charge) ratios if possible.

Review the fragments and ensure that the most stable and abundant ions are represented. These are the ions most likely to appear as peaks in the mass spectrum. Consider factors such as resonance stabilization, inductive effects, and hyperconjugation when predicting fragment stability.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

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

Mass Spectrometry

Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio of ions. It involves ionizing chemical species and sorting the ions based on their mass. The resulting mass spectrum provides information about the molecular weight and structure of the compounds, allowing chemists to identify fragments and deduce structural features.

Fragmentation Patterns

Fragmentation patterns refer to the specific ways in which a molecule breaks apart during ionization in mass spectrometry. These patterns are influenced by the molecular structure and stability of the resulting fragments. Understanding common fragmentation pathways helps predict the principal fragments that will appear in the mass spectrum of a compound.

Curved Arrows in Mechanisms

Curved arrows are used in organic chemistry to represent the movement of electrons during chemical reactions and mechanisms. They indicate the flow of electron density, showing how bonds are formed or broken. In the context of mass spectrometry, using curved arrows can help illustrate the fragmentation process and the formation of specific ion fragments from the parent molecule.

Watch next

Master Ionization Potentials with a bite sized video explanation from Johnny

Start learning

Related Videos

Related Practice

Textbook Question

Using curved arrows, show the principal fragments you would expect to see in the mass spectrum of each of the following compounds:

Textbook Question

Using curved arrows, show the principal fragments you would expect to see in the mass spectrum of each of the following compounds:

Textbook Question

Primary alcohols have a strong peak at m/z = 31.

a. What fragment is responsible for this peak?

Textbook Question

What distinguishes the mass spectrum of 2,2-dimethylpropane from the mass spectra of pentane and isopentane?

Textbook Question

The mass spectra of 1-methoxybutane, 2-methoxybutane, and 2-methoxy-2-methylpropane are shown below. Match each compound with its spectrum.

<IMAGE>

Textbook Question

The reaction of (Z)-2-pentene with water and a trace of H₂SO₄ forms two products. Identify the products from their mass spectra.

<IMAGE>

Textbook Question

A mass spectrum shows significant peaks at m/z = 87, 115, 140, and 143. Which of the following compounds is responsible for that mass spectrum?

Textbook Question

The mass spectrum for a compound with molecular weight of 102 is shown below. Its IR spectrum has a broad, strong absorption at 3600 cm^–1 and a medium absorption at 1360 cm^–1.

b. Show the mechanism for formation of the peak at m/z = 84.

<IMAGE>

Show more practices

Download the Mobile app

Privacy

Do not sell my personal information

Accessibility

Patent notice

Sitemap

Using curved arrows, show the principal fragments you would expect to see in the mass spectrum of each of the following compounds:c.

Key Concepts

Mass Spectrometry

Fragmentation Patterns

Curved Arrows in Mechanisms

Watch next

Using curved arrows, show the principal fragments you would expect to see in the mass spectrum of each of the following compounds:
c.