Textbook Question
Describe the 1H NMR spectrum you would expect for each of the following compounds, indicating the relative positions of the signals:
i.
915
views
15. Analytical Techniques:IR, NMR, Mass Spect
1H NMR:Spin-Splitting (N + 1) Rule
Struggling with Organic Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Predict the splitting pattern (multiplicity) for the following molecule:
A
A=singlet; B=doublet; C=singlet
B
A=singlet; B=singlet; C=doublet
C
A=doublet; B=singlet; C=doublet
D
A=singlet; B=singlet; C=singlet
Verified step by step guidance1
Identify the hydrogen environments in the molecule. In the given structure, there are three distinct groups labeled A, B, and C.
Consider the group labeled A. It is a methyl group (CH₃) attached to a quaternary carbon, which means it has no neighboring hydrogens to couple with. Therefore, the splitting pattern for A is a singlet.
Examine the group labeled B. This is a methylene group (CH₂) adjacent to a carbonyl group (C=O). The carbonyl group does not have any hydrogens, and the adjacent quaternary carbon also lacks hydrogens. Thus, B will also appear as a singlet.
Look at the group labeled C. It is another methyl group (CH₃) attached to a carbonyl group. Similar to A, there are no neighboring hydrogens to cause splitting, so C will appear as a singlet.
Summarize the splitting patterns: A=singlet, B=singlet, C=singlet. This is consistent with the correct answer provided.
12:21mWatch next
Master Splitting without J-values with a bite sized video explanation from Johnny
Start learningRelated Videos
Related Practice
1H NMR:Spin-Splitting (N + 1) Rule practice set
Problem sets built by lead tutorsExpert video explanations