Textbook Question
For the following molecules, give the integration you would expect for the signal associated with the hydrogens at the labeled carbons. [Pay attention to the symmetry, or lack of symmetry, in the molecules.]
(f)
1010
views
Ch. 15 - Structural Identification II: Nuclear Magnetic Resonance Spectroscopy
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 2 - General Chemistry Translated: Finding the Electrons114
- Ch. 3 - Alkanes and Cycloalkanes: Properties and Conformational Analysis109
- Ch. 4 - Acids and Bases: Electron Flow144
- Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics118
- Ch. 6 - Stereoisomerism: Arrangement of Atoms in Space112
- Ch. 7 - Principles of Green (Organic) Chemistry3
- Ch. 8 - Alkenes I: Properties and Electrophilic Additions158
- Ch. 9 - Alkenes II: Oxidation and Reduction150
- Ch. 10 - Alkynes: Electrophilic Addition and Redox Reactions101
- Ch. 11 - Properties and Synthesis of Alkyl Halides: Radical Reactions108
- Ch. 12 - Substitution and Elimination: Reactions of Haloalkanes172
- Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination239
- Ch. 14 - Structural Identification I: Infrared Spectroscopy and Mass Spectrometry54
- Ch. 15 - Structural Identification II: Nuclear Magnetic Resonance Spectroscopy93
- Ch. 16 - Metals in Organic Chemistry48
- Ch. 17 - Carbonyl Addition Reactions: Aldehydes and Ketones45
- Ch. 18 - Nucleophilic Acyl Substitution I: Carboxylic Acids18
- Ch. 19 - Nucleophilic Acyl Substitution II: Carboxylic Acid Derivatives39
- Ch. 20 - Enolates: Carbonyl Addition and Substitution13
- Ch. 21 - Conjugated Systems I: Stability and Addition Reactions56
- Ch. 22 - Conjugated Systems II: Pericyclic Reactions54
- Ch. 23 - Benzene I: Aromatic Stability and Substitution Reactions64
- Ch. 24 - Benzene II: Reactions Influenced by the Aromatic Ring62
- Ch. 25 - Amines: Structure, Reactions, and Synthesis27
- Ch. 26 - Amino Acids, Proteins, and Peptide Synthesis9
- Ch. 27 - Carbohydrates, Nucleic Acids, and Lipids54
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
All textbooks
Mullins 1st EditionCh. 15 - Structural Identification II: Nuclear Magnetic Resonance SpectroscopyProblem 59e
Mullins 1st EditionCh. 15 - Structural Identification II: Nuclear Magnetic Resonance SpectroscopyProblem 59eChapter 14, Problem 59e
For the following molecules, give the chemical shift for each indicated hydrogen.
(e) 
Verified step by step guidance1
Identify the molecular structure and locate the hydrogen atoms for which the chemical shift needs to be determined. This involves understanding the environment around each hydrogen atom, including nearby atoms and functional groups.
Consider the electronic environment of each hydrogen atom. Chemical shifts in NMR spectroscopy are influenced by the electron density around the hydrogen. Electronegative atoms or groups can deshield the hydrogen, causing a downfield shift (higher ppm value).
Analyze the hybridization of the carbon atom to which the hydrogen is attached. For example, hydrogens attached to sp3 hybridized carbons typically appear upfield (lower ppm), while those attached to sp2 or sp hybridized carbons appear downfield.
Take into account any aromatic or conjugated systems. Hydrogens in aromatic systems, such as benzene rings, often appear in a distinct chemical shift range due to the ring current effect.
Use reference tables or literature values to estimate the chemical shift range for each type of hydrogen in the molecule. Compare the environments of the hydrogens in your molecule to these standard values to predict their chemical shifts.
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.
Chemical Shift
Chemical shift refers to the position on the NMR spectrum where a particular hydrogen atom resonates. It is influenced by the electronic environment surrounding the hydrogen, which affects its magnetic field. The chemical shift is measured in parts per million (ppm) and provides insights into the structure and functional groups present in the molecule.
Recommended video:
Guided course
11:44
1H NMR Chemical Shifts
Shielding and Deshielding
Shielding occurs when electrons around a hydrogen atom create a local magnetic field that opposes the external magnetic field, resulting in a lower chemical shift. Deshielding happens when the electron density is reduced, often due to electronegative atoms or groups, leading to a higher chemical shift. Understanding these effects is crucial for predicting chemical shifts in NMR spectroscopy.
Recommended video:
Guided course
04:18Ranking Shielded Protons
Functional Groups and Their Influence
Functional groups significantly impact the chemical shift of hydrogens in a molecule. For instance, hydrogens attached to carbon atoms near electronegative atoms or within aromatic rings typically exhibit higher chemical shifts due to deshielding. Recognizing the presence and type of functional groups helps in estimating the chemical shift values accurately.
Recommended video:
Guided course
02:36Identifying Functional Groups
Related Practice
Textbook Question
For the following molecules, give the chemical shift for each indicated hydrogen.
(b)
764
views
Textbook Question
Predict the splitting pattern for each of the indicated hydrogens in Assessment 15.59.
(a)
1110
views
Textbook Question
Predict the splitting pattern for each of the indicated hydrogens in Assessment 15.59.
(c)
1032
views
Textbook Question
Predict the splitting pattern for each of the indicated hydrogens in Assessment 15.59.
(b)
954
views
Textbook Question
For the following molecules, give the chemical shift for each indicated hydrogen.
(d)
1118
views