Question 1

How could you tell the difference between these two compounds with 1H NMR?

Accepted Answer

Both spectra would show the sa

Question 2

________ is commonly used as an internal reference in NMR spectroscopy; its signal is assigned δ = 0 in 1H and 13C NMR spectroscopy.

Accepted Answer

Tetramethy

Question 3

Any process faster than ________ will be recorded as an average by NMR spectroscopy.

Accepted Answer

A)  0.0005 seconds 
B)  0.1 seconds 
C)  0.01 seconds 
D)  0.001 seconds 
E)  1 minute 
A)  0.0005 seconds 
B)  0.1 seconds 
C)  0.01 seconds 
D)  0.001 seconds 
E)  1 minute

Question 4

What is the relative area of each peak in a quartet spin-spin splitting pattern?

Accepted Answer

A)  1:2:1 
B)  1:2:2:1 
C)  1:1:1:1 
D)  1:4:4:1 
E)  1:3:3:1 
A)  1:2:1 
B)  1:2:2:1 
C)  1:1:1:1 
D)  1:4:4:1 
E)  1:3:3:1

Question 5

Predict the number of distinct quartets expected in the off-resonance decoupled   
spectrum of the compound shown below.

Accepted Answer

The answer of Predict the number of distinct quartets expected...

Question 6

Draw the 13C NMR spectrum for the following compound.

Accepted Answer

Question 7

Deduce the identity of the following compound from the 1H NMR data given.
C4H11N: δ 0.90 (3H, triplet), 1.07 (3H, doublet), 1.14 (2H, broad singlet), 1.34 (2H, multiplet), 2.79 (1H, multiplet) (ppm)

Accepted Answer

Question 8

What type of carbon environment does not generate a signal in the DEPT-90 spectrum and gives a negative signal in the DEPT-135 spectrum?

Accepted Answer

A)  quaternary 
B)  methine 
C)  methylene 
D)  methyl 
E)  carbonyl 
A)  quaternary 
B)  methine 
C)  methylene 
D)  methyl 
E)  carbonyl

Question 9

Deduce the identity of the following compound from the 1H NMR data given.
C3H3Cl5: δ 4.5 (1H, triplet), 6.1 (2H, doublet) (ppm)

Accepted Answer

Question 10

Deduce the identity of the following compound from the 1H NMR data given.
C7H12O4: δ 1.3 (6H, triplet), 3.4 (2H, singlet), 4.2 (4H, quartet) (ppm)

Accepted Answer

Question 11

Deduce the identity of the following compound from the 1H NMR data given.
C3H6Br2: δ 2.4 (2H, quintet), 3.5 (4H, triplet) (ppm)

Accepted Answer

Question 12

Provide a structure that is consistent with the data below.
C7H16O
IR (cm-1): 3200-3600 (broad), 2950
1H NMR ( d): 2.9 (1H, broad s), 1.2 (6H, q), 0.9 (9H, t)
13C NMR (d ): 70 (s), 25 (t), 12 (q)

Accepted Answer

Question 13

A compound (C5H8O) shows IR absorptions at 3600 and 3300 cm-1. Its 1H NMR spectrum contained singlets at   
and 2.9 (broad) (ppm) in a ratio of 6:1:1. Name this compound.

Accepted Answer

2-methylbu

Question 14

Predict the number of signals expected (disregarding splitting) in the 1H spectrum of 1,1-dimethylcyclobutane.

Accepted Answer

Question 15

Deduce the identity of the following compound from the spectral data given.
C5H10O: 1H NMR, δ 1.2 (6H, doublet), 2.1 (3H, singlet), 2.8 (1H, septet) (ppm); IR, 2980, 1710 cm-1; MS, m/z 71, 43

Accepted Answer

Question 16

Provide a structure that is consistent with the data below.
C7H16O
IR (cm-1): 3200-3600 (broad), 2950
1H NMR ( d): 2.8 (1H, broad s), 1.0 (6H, s), 0.9 (9H, s)
13C NMR (d ): 68 (s), 39 (s), 16 (q), 13 (q)

Accepted Answer

Question 17

Deduce the identity of the following compound from the 13C NMR data given.
C4H7Br: δ 18.0 (quartet), 33.0 (triplet), 128.0 (doublet), 131.0 (doublet) (ppm)

Accepted Answer

Question 18

The following splitting pattern represents one of the vinyl protons of styrene. Identify which proton is represented and list all the coupling constants (J values) for the splitting pattern.

Accepted Answer

H_b, J_ab = 10

Question 19

Deduce the identity of the following compound from the 13C NMR data given.
C4H10O: δ 10.0 (quartet), 22.9 (quartet), 32.0 (triplet), 69.6 (doublet) (ppm)

Accepted Answer

Question 20

Deduce the identity of the following compound from the 13C NMR data given.
C8H8O: δ 26.4 (quartet), 128.0 (doublet), 128.3 (doublet), 133.0 (doublet), 137.0 (singlet), 198.0 (singlet) (ppm)

Accepted Answer

acetopheno

Exam 13: Nuclear Magnetic Resonance Spectroscopy

How could you tell the difference between these two compounds with 1H NMR?

________ is commonly used as an internal reference in NMR spectroscopy; its signal is assigned δ = 0 in 1H and 13C NMR spectroscopy.

Any process faster than ________ will be recorded as an average by NMR spectroscopy.

What is the relative area of each peak in a quartet spin-spin splitting pattern?

Predict the number of distinct quartets expected in the off-resonance decoupled spectrum of the compound shown below.

Draw the 13C NMR spectrum for the following compound.

Deduce the identity of the following compound from the 1H NMR data given. C4H11N: δ 0.90 (3H, triplet), 1.07 (3H, doublet), 1.14 (2H, broad singlet), 1.34 (2H, multiplet), 2.79 (1H, multiplet) (ppm)

What type of carbon environment does not generate a signal in the DEPT-90 spectrum and gives a negative signal in the DEPT-135 spectrum?

Deduce the identity of the following compound from the 1H NMR data given. C3H3Cl5: δ 4.5 (1H, triplet), 6.1 (2H, doublet) (ppm)

Deduce the identity of the following compound from the 1H NMR data given. C7H12O4: δ 1.3 (6H, triplet), 3.4 (2H, singlet), 4.2 (4H, quartet) (ppm)

Deduce the identity of the following compound from the 1H NMR data given. C3H6Br2: δ 2.4 (2H, quintet), 3.5 (4H, triplet) (ppm)

Provide a structure that is consistent with the data below. C7H16O IR (cm-1): 3200-3600 (broad), 2950 1H NMR ( d): 2.9 (1H, broad s), 1.2 (6H, q), 0.9 (9H, t) 13C NMR (d ): 70 (s), 25 (t), 12 (q)

A compound (C5H8O) shows IR absorptions at 3600 and 3300 cm-1. Its 1H NMR spectrum contained singlets at and 2.9 (broad) (ppm) in a ratio of 6:1:1. Name this compound.

Predict the number of signals expected (disregarding splitting) in the 1H spectrum of 1,1-dimethylcyclobutane.

Deduce the identity of the following compound from the spectral data given. C5H10O: 1H NMR, δ 1.2 (6H, doublet), 2.1 (3H, singlet), 2.8 (1H, septet) (ppm); IR, 2980, 1710 cm-1; MS, m/z 71, 43

Provide a structure that is consistent with the data below. C7H16O IR (cm-1): 3200-3600 (broad), 2950 1H NMR ( d): 2.8 (1H, broad s), 1.0 (6H, s), 0.9 (9H, s) 13C NMR (d ): 68 (s), 39 (s), 16 (q), 13 (q)

Deduce the identity of the following compound from the 13C NMR data given. C4H7Br: δ 18.0 (quartet), 33.0 (triplet), 128.0 (doublet), 131.0 (doublet) (ppm)

The following splitting pattern represents one of the vinyl protons of styrene. Identify which proton is represented and list all the coupling constants (J values) for the splitting pattern.

Deduce the identity of the following compound from the 13C NMR data given. C4H10O: δ 10.0 (quartet), 22.9 (quartet), 32.0 (triplet), 69.6 (doublet) (ppm)

Deduce the identity of the following compound from the 13C NMR data given. C8H8O: δ 26.4 (quartet), 128.0 (doublet), 128.3 (doublet), 133.0 (doublet), 137.0 (singlet), 198.0 (singlet) (ppm)

Structure and Bonding

Acids and Bases; Functional Groups

Structure and Stereochemistry of Alkanes

The Study of Chemical Reactions

Stereochemistry

Alkyl Halides; Nucleophilic Substitution

Structure and Synthesis of Alkenes; Elimination

Reactions of Alkenes

Structure and Synthesis of Alcohols

Reactions of Alcohols

Infrared Spectroscopy and Mass Spectrometry

Ethers, Epoxides, and Thioethers

Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy

Aromatic Compounds

Reactions of Aromatic Compounds

Ketones and Aldehydes

Amines

Carboxylic Acids

Carboxylic Acid Derivatives

Condensations and Alpha Substitutions of Carboxyl Compounds

Carbohydrates and Nucleic Acids

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

How could you tell the difference between these two compounds with ¹H NMR?

________ is commonly used as an internal reference in NMR spectroscopy; its signal is assigned δ = 0 in ¹H and ¹³C NMR spectroscopy.

Draw the ¹³C NMR spectrum for the following compound.

Deduce the identity of the following compound from the ¹H NMR data given. C₄H₁₁N: δ 0.90 (3H, triplet), 1.07 (3H, doublet), 1.14 (2H, broad singlet), 1.34 (2H, multiplet), 2.79 (1H, multiplet) (ppm)

Deduce the identity of the following compound from the ¹H NMR data given. C₃H₃Cl₅: δ 4.5 (1H, triplet), 6.1 (2H, doublet) (ppm)

Deduce the identity of the following compound from the ¹H NMR data given. C₇H₁₂O₄: δ 1.3 (6H, triplet), 3.4 (2H, singlet), 4.2 (4H, quartet) (ppm)

Deduce the identity of the following compound from the ¹H NMR data given. C₃H₆Br₂: δ 2.4 (2H, quintet), 3.5 (4H, triplet) (ppm)

Provide a structure that is consistent with the data below. C₇H₁₆O IR (cm^-1): 3200-3600 (broad), 2950 ¹H NMR ( d): 2.9 (1H, broad s), 1.2 (6H, q), 0.9 (9H, t) ¹³C NMR (d ): 70 (s), 25 (t), 12 (q)

A compound (C₅H₈O) shows IR absorptions at 3600 and 3300 cm^-1. Its ¹H NMR spectrum contained singlets at and 2.9 (broad) (ppm) in a ratio of 6:1:1. Name this compound.

Predict the number of signals expected (disregarding splitting) in the ¹H spectrum of 1,1-dimethylcyclobutane.

Deduce the identity of the following compound from the spectral data given. C₅H₁₀O: ¹H NMR, δ 1.2 (6H, doublet), 2.1 (3H, singlet), 2.8 (1H, septet) (ppm); IR, 2980, 1710 cm^-1; MS, m/z 71, 43

Provide a structure that is consistent with the data below. C₇H₁₆O IR (cm^-1): 3200-3600 (broad), 2950 ¹H NMR ( d): 2.8 (1H, broad s), 1.0 (6H, s), 0.9 (9H, s) ¹³C NMR (d ): 68 (s), 39 (s), 16 (q), 13 (q)

Deduce the identity of the following compound from the ¹³C NMR data given. C₄H₇Br: δ 18.0 (quartet), 33.0 (triplet), 128.0 (doublet), 131.0 (doublet) (ppm)

Deduce the identity of the following compound from the ¹³C NMR data given. C₄H₁₀O: δ 10.0 (quartet), 22.9 (quartet), 32.0 (triplet), 69.6 (doublet) (ppm)

Deduce the identity of the following compound from the ¹³C NMR data given. C₈H₈O: δ 26.4 (quartet), 128.0 (doublet), 128.3 (doublet), 133.0 (doublet), 137.0 (singlet), 198.0 (singlet) (ppm)