ch16-ques-2013

Chapter Sixteen Topic: Introduction to NMR Section: 16.1 Difficulty Level: Easy

1.

Which of the following can not be probed by an NMR spectrometer?

A) nucleus with odd number of protons & odd number of neutrons B) nucleus with odd number of protons &even number of neutrons C) nucleus with even number of protons & odd number of neutrons D) nucleus with even number of protons & even number of neutrons E) none of these

Ans: D Topic: Introduction to NMR Section: 16.1 Difficulty Level: Easy

2.

How many nuclear spin states are possible for the 1H nucleus?

A) 1 B) 2 C) 4 D) 5 E) none of these

Ans: B Topic: Introduction to NMR Section: 16.1 Difficulty Level: Easy

3.

Which of the following electromagnetic radiation is used in NMR spectroscopy?

A) UV B) IR C) visible D) γ-rays E) radio wave

Ans: E Topic: Introduction to NMR Section: 16.1 Difficulty Level: Medium

4.

_______ protons experience a net magnetic field strength that is smaller than the applied magnetic field.

A) deshielded B) shielded C) paramagnetic D) diamagnetic E) none of these

Ans: B Topic: Introduction to NMR Section: 16.1 Difficulty Level: Medium

5.

_______ protons experience a net magnetic field strength that is higher than the applied magnetic field.

A) deshielded B) shielded C) paramagnetic D) diamagnetic E) none of these

Ans: A Topic: Acquiring a 1HNMR spectrum Section: 16.2 Difficulty Level: Medium

6.

Which of the following is true about the relationship between the energy gap (ΔE) between the spin states for a 1H nucleus and the strength of the external magnetic field?.

A) they are inversely proportional B) they are directly proportional C) there is no relationship D) the magnetic field is slightly less E) none of these

Ans: B Topic: Acquiring a 1HNMR spectrum Section: 16.2 Difficulty Level: Medium

7.

The strength of the magnetic field is a determining factor for the range of _______that must be used for NMR spectrometer.

A) temperature B) frequencies C) tesla D) spin states D) none of these

Ans: B Topic: Acquiring a 1HNMR spectrum Section: 16.2 Difficulty Level: Easy

8.

Which of the following is not a common solvent used for acquiring a 1H NMR spectrum?

A) CDCl3 B) CCl4 C) CD3CN D) CH3OH E) D2O

Ans: D Topic: Characteristics of a 1HNMR spectrum Section: 16.3 Difficulty Level: Easy

9.

Which of the following is true about the number of signals in a 1H NMR spectrum?

A) it indicates the number of neighboring protons B) it indicates the electronic environment of neighboring protons C) it indicates the number of different kinds of protons D) it indicates the electronic environment of absorbing protons E) it indicates the number of protons in the signal

Ans: C Topic: Characteristics of a 1HNMR spectrum Section: 16.3 Difficulty Level: Easy

10.

Which of the following is true about the location of signals in a 1H NMR spectrum?

A) it indicates the number of neighboring protons B) it indicates the electronic environment of neighboring protons C) it indicates the number of different protons D) it indicates the electronic environment of absorbing protons E) it indicates the number of protons in the signal

Ans: D Topic: Characteristics of a 1HNMR spectrum Section: 16.3 Difficulty Level: Easy

11.

Which of the following is true about the area under each signal in a 1H NMR spectrum?


Ans: E Topic: Characteristics of a 1HNMR spectrum Section: 16.3 Difficulty Level: Easy

12.

Which of the following is true about the shape of the signal in a 1H NMR spectrum?


Ans: A Topic: Number of signals Section: 16.4 Difficulty Level: Medium

13.

Which of the following type of protons are chemically non equivalent?

A) homotopic B) enantiotopic C) diastereotopic D) A & B E) B & C

Ans: C Topic: Number of signals Section: 16.4 Difficulty Level: Medium

14.

Which of the following type of protons are chemically equivalent?

A) homotopic B) enantiotopic C) diastereotopic D) A & B E) B & C

Ans: D Topic: Number of signals Section: 16.4 Difficulty Level: Easy

15.

Protons Ha and Hb in the following compound are _________. Ha Hb

A) homotopic B) enantiotopic C) diastereotopic D) mesotopic E) none of these

Ans: A Topic: Number of signals Section: 16.4 Difficulty Level: Easy

16.

Protons Ha and Hb in the following compound are _________. Ha Hb


Ans: B Topic: Number of signals Section: 16.4 Difficulty Level: Medium

17.

Protons Ha and Hb in the following compound are _________.

Hb

Ha



18.

Protons Ha and Hb in the following compound are _________. Br

Ha

H

Hb



19.

Protons Ha and Hb in the following compound are _________. OH

HbHa



20.

Protons Ha and Hb in the following compound are _________.

Ha

Hb


Ans: C Topic: Number of signals Section: 16.4 Difficulty Level: Easy

21.

How many signals would you expect to find in the 1H NMR spectrum of CH3OCH2CH3?

A) 1 B) 2 C) 3 D) 4 E) 5

Ans: C Topic: Number of signals Section: 16.4 Difficulty Level: Easy

22.

How many signals would you expect to find in the 1H NMR spectrum of CH3OCH2CH2OCH3?

A) 1 B) 2 C) 3 D) 4 E) 5

Ans: B Topic: Number of signals Section: 16.4 Difficulty Level: Easy

23.

How many signals would you expect to find in the 1H NMR spectrum of (CH3)2CHCH2CH2CH3?

A) 1 B) 2 C) 3 D) 4 E) 5

Ans: E Topic: Number of signals Section: 16.4 Difficulty Level: Medium

24.

How many signals would you expect to find in the 1H NMR spectrum of HOCH2CH2CH2CH2OH?

A) 1 B) 2 C) 3 D) 4 E) 5


25.

How many signals would you expect to find in the 1H NMR spectrum of the following compound?

A) 4 B) 5 C) 6 D) 7 E) 8

Ans: D Topic: Number of signals Section: 16.4 Difficulty Level: Medium

26.


O

O A) 4 B) 5 C) 6 D) 7 E) 8

Ans: B Topic: Number of signals Section: 16.4 Difficulty Level: Medium

27.

How many signals would you expect to find in the 1H NMR spectrum of the following compound? O OH

A) 4 B) 5 C) 6 D) 7 E) 9

Ans: D Topic: Number of signals Section: 16.4 Difficulty Level: Medium

28.


O

O

Ans: 4

Topic: Number of signals Section: 16.4 Difficulty Level: Medium

29.


O

Cl

O

Ans: 6

Topic: Number of signals Section: 16.4 Difficulty Level: Medium

30.


OO

Ans: 3

Topic: Chemical shift Section: 16.5 Difficulty Level: Medium

31.

The 1H NMR spectrum of bromoethane shows a signal at 3.5ppm when the spectrum is recorded using a 60-MHz spectrometer. Where do you expect to see the signal if a 300-MHz instrument is used instead?

A) 3.5 ppm B) 7.5 ppm C) 6.8 ppm D) 5.8 ppm E) none of these

Ans: A Topic: Chemical shift Section: 16.5 Difficulty Level: Easy

32.

______is used as a reference for recording NMR spectroscopy and is assigned a chemical shift value of zero. Ans: Tetramethylsilane (TMS)/ (CH3)4Si

Topic: Chemical shift Section: 16.5 Difficulty Level: Easy

33.

Which of the indicated protons in the following compound would appear most downfield in the 1H NMR spectrum?

I

II IV

OH

III

A) I B) II C) III D) IV

Ans: D Topic: Chemical shift Section: 16.5 Difficulty Level: Medium

34.

Which of the indicated protons in the following compound would appear most downfield in the 1H NMR spectrum?

III III

IV

C CH3C

H

C

H

FH

H H

H

V

A) I B) II C) III D) IV E) V

Ans: E Topic: Chemical shift Section: 16.5 Difficulty Level: Hard

35.

Which of the indicated protons in the following compound would appear most upfield in the 1H NMR spectrum?

I III

O

O O

F

II IV

A) I B) II C) III D) IV E) I & III

Ans: A Topic: Chemical shift Section: 16.5 Difficulty Level: Easy

36.

Which of the following is a correct prediction of the chemical shifts for the signals in the 1H NMR spectrum for the following compound?

IIIII

HO

OI

A) I=3.7 ppm, II=2.7 ppm, III=1.9 ppm B) I=3.7 ppm, II=2.2 ppm, III=1.9 ppm C) I=3.9 ppm, II=2.7 ppm, III=1.9 ppm D) I=3.9 ppm, II=2.2 ppm, III=2.4 ppm E) none of these

Ans: C Topic: Chemical shift Section: 16.5 Difficulty Level: Easy

37.


IVIIII

OO

II

A) I=3.9 ppm, II=4.2 ppm, III=2.2 ppm, IV=3.4 ppm B) I=3.4 ppm, II=2.2 ppm, III=2.2 ppm, IV=3.4 ppm C) I=3.4 ppm, II=2.2 ppm, III=4.2 ppm, IV=3.4 ppm D) I=3.4 ppm, II=4.2 ppm, III=4.2 ppm, IV=3.4 ppm E) none of these

Ans: D Topic: Chemical shift Section: 16.5 Difficulty Level: Medium

38.


II IV

O

OIIII


Ans: A Topic: Chemical shift Section: 16.5 Difficulty Level: Medium

39.


IIIV

O

O IIII O


Ans: B Topic: Chemical shift Section: 16.5 Difficulty Level: Hard

40.

Predict the chemical shifts for the signals in the 1H NMR spectrum for the following compound.

O

O

O

OI

II

III

IV

Ans:

5.7 ppm

O

O

O

O

1.9 ppm4.4 ppm

5.2 ppm Topic: Chemical shift Section: 16.5 Difficulty Level: Hard

41.

Predict the chemical shifts for the signals in the 1H NMR spectrum for the following compound?

O

O O

Ans:

O

O O4.2 ppm

2.7 ppm 2.2 ppm1.9 ppm

1.4 ppm

0.9 ppm Topic: Chemical shift Section: 16.5 Difficulty Level: Medium

42.

Aromatic protons produce signal in the range of 7-8 ppm, due to the _________effect of π electrons

A) diamagnetic anisotropy B) paramagnetic anisotropy C) diamagnetic isotropy D) paramagnetic isotropy E) none of these

Ans: A Topic: Chemical shift Section: 16.5 Difficulty Level: Medium

43.

Which of the following protons appear most upfield in the 1H NMR spectrum?

HH

H

II III

IV

HI A) I B) II C) III D) IV E) none of these

Ans: D

Topic: Integration Section: 16.6 Difficulty Level: Medium

44.

A compound with molecular formula C8H14 has the following 1H NMR spectrum. Which of the following is the correct number of protons giving rise to each signal?

A) I-3H, II-9H, III-2H B) I-2H, II-9H, III-3H C) I-4H, II-6H, III-4H D) none of these

Ans: A Topic: Integration Section: 16.6 Difficulty Level: Medium

0 1 2 3 4 5 6 7 8 PPM

III

II

I

45.

A compound with molecular formula C6H11N has the following 1H NMR spectrum. Which of the following is the correct number of protons giving rise to each signal?

A) I-6H, II-3H, III-2H B) I-5H, II-4H, III-2H C) I-6H, II-4H, III-1H D) none of these

Ans: C Topic: Integration Section: 16.6 Difficulty Level: Medium

0 1 2 3 4 5 6 7 8 PPM

III

II

I

46.

A compound with molecular formula C8H10O has the following 1H NMR spectrum. Which of the following is the correct number of protons giving rise to each signal?

SDBS: National Institute of Advanced Industrial Science and Technology Ans: I-3H, II-2H, III-3H, IV-2H

Topic: Multiplicity Section: 16.7 Difficulty Level: Medium

47.

Which of the following four compounds gives a 1H NMR spectrum consisting of only a singlet?

A) 1,1-dichloropropane B) 1,3-dichloropropane C) 1,2-dichloropropane D) 2,2-dichloropropane E) none of these

Ans: D Topic: Multiplicity Section: 16.7 Difficulty Level: Medium

I

II III

IV

48.

How many 1H NMR signals will 2-chloro-3-methyl-2-butene exhibit?


Ans: C Topic: Multiplicity Section: 16.7 Difficulty Level: Medium

49.

Which of the following compounds will display two triplets and a singlet in the 1H NMR spectrum?

A) CH3CH(OCH3)2 B) CH3OCH2CH2OCH3 C) CH3OCH2CH(OH)CH3 D) CH3OCH2CH2CH2CH2OCH3 E) none of these

Ans: D Topic: Multiplicity Section: 16.7 Difficulty Level: Hard

50. Which of the following compounds will display a singlet, a triplet and a quartet in the 1H NMR spectrum?

A) 2-chloro-4-methylpentane B) 3-chloro-2-methylpentane C) 3-chloropentane D) 1-chloro-2,2-dimethylbutane E) 3-chloro-3-methylpentane

Ans: E Topic: Multiplicity Section: 16.7 Difficulty Level: Medium

51.

Determine the multiplicity of each signal in the expected 1H NMR spectrum of the following compound.

O Ans:

O

doublet septet

triplet

quartet

Topic: Multiplicity Section: 16.7 Difficulty Level: Easy

52.


NH

O

Ans:

NH

O

singlet

singlet

triplettriplet

sextet

singlet Topic: Multiplicity Section: 16.7 Difficulty Level: Medium

53.


O

O Ans:

O

O

singlet

doublet

doublet

multiplet


54.


O

H

O

Ans:

O

H

O

singlet

singlet

singlet doublet

doublet

sextet


55.


O NH2HO

O

Ans:

O NH2HO

O

singlettriplet

triplet singlet

singlet

Topic: Multiplicity Section: 16.7 Difficulty Level: Hard

56.

Determine the multiplicity of each signal in the expected 1H NMR spectrum of 2,3-dimethyl-2-pentanol. Ans:

singlet

OH

singlet

triplet

quintet

sextetdoublet


57.

The coupling constant (J) for bromoethane is 7 Hz when the 1H NMR spectrum is acquired at 250 MHz. What is the coupling constant between these protons when the spectrum is acquired at 500 MHz?

A) 3.5 Hz B) 7 Hz C) 14 Hz D) 21 Hz E) none of these

Ans: B Topic: Multiplicity Section: 16.7 Difficulty Level: Hard

58.

Which of the following is the maximum multiplicity observed for Hc protons in the following compound? Assume that Jcd and Jcb values are different.

HN

a b

c

d A) 5 B) 6 C) 8 D) 12 E) none of these

Ans: D Topic: Multiplicity Section: 16.7 Difficulty Level: Hard

59.

Which of the following is the maximum multiplicity observed for Hb protons in the following compound? Assume that Jab and Jbc values are different.

O

a

a

b

cd


Ans: C Topic: Multiplicity Section: 16.7 Difficulty Level: Hard

60.

Presence of which of the following protons is confirmed by D2O exchange?

A) OH B) NH2 C) CH D) A & B E) none of these

Ans: D Topic: 1H NMR spectrum Section: 16.8 Difficulty Level: Medium

61.

Determine the multiplicity and predict the chemical shifts of each signal in the expected 1H NMR spectrum of the following compound.

II IV

O

OIIII

Ans:

sextet singlet

O

Otriplettriplet0.9 ppm

1.7 ppm

3.9 ppm

2.4 ppm Topic: 1H NMR spectrum Section: 16.8 Difficulty Level: Medium

62.


O

OO

Ans:

O

OO

triplet

sextet

doublet1.1 ppm

septet3.2 ppm 1.4 ppm

0.9 ppmtriplet2.7 ppm

Topic: 1H NMR spectrum Section: 16.8 Difficulty Level: Medium

63.


O

O

O

O Ans:

5.7 ppm

O

O

O

O

singlet4.4 ppm

5.2 ppm

1.9 ppm

singlettriplet

doublet

Topic: 1H NMR spectroscopy to distinguish between compounds Section: 16.9 Difficulty Level: Medium

64.

How would you use 1H NMR spectroscopy to distinguish between the following two compounds?

H

O

O

H

O O

III

A) I=3 & II=2 signals B) I=4 & II=3 signals C) I=5 & II=3 signals D) none of these

Ans: B Topic: 1H NMR spectroscopy to distinguish between compounds Section: 16.9 Difficulty Level: Medium

65.


I IIO O

O O

Ans: Both compounds will have three signals.

Compound I: a triplet, a quartet and a singlet Compound II: a singlet, a triplet and a quintet


66.


O

O

I IIO

O

Ans: Both compounds will have five signals.

Compound I: a doublet, a septet, two triplets and a sextet. Compound II: a doublet, a multiplet, a quartet and a triplet.


67.


O

O

O

OI II

Ans: Both compounds will have five signals. The Ha proton in compound I will appear more downfield than the Ha proton in compound II.

O

O

O

OI IIa a

Topic: Analyzing a 1H NMR spectrum Section: 16.10 Difficulty Level: Medium

68.

A compound with a molecular formula C9H12 has the following 1H NMR spectrum. Which of the following structures is consistent with this spectrum?

01234567PPM

9

3

I II III IV

A) I B) II C) III D) IV E) none of these

Ans: C Topic: Analyzing a 1H NMR spectrum Section: 16.10 Difficulty Level: Medium

69.

Which of the following structures is consistent with this 1H NMR spectrum?

SDBS: National Institute of Advanced Industrial Science and Technology

OO O

I II III IV A) I B) II C) III D) IV E) none of these

Ans: B Topic: Analyzing a 1H NMR spectrum Section: 16.10 Difficulty Level: Medium

1 1

5

3

70.

A compound with a molecular formula C9H10O2 has the following 1H NMR spectrum. Which of the following structures is consistent with this spectrum?

H

O

OOH

O

O

I II III IV


Ans: B Topic: Analyzing a 1H NMR spectrum Section: 16.10 Difficulty Level: Medium

0 2 4 6 8 10 12 PPM

71.

A compound with a molecular formula C5H10O has the following 1H NMR spectrum. Propose a structure for this compound.

0246810PPM

Ans:

H

O Topic: Analyzing a 1H NMR spectrum Section: 16.10 Difficulty Level: Medium

72.

Propose a structure for a compound with molecular formula C5H11Cl, that fits the following spectroscopic data: 1H NMR: 0.9δ (triplet, I=3), 1.3δ (sextet, I=2), 1.5δ (quartet, I=2), 1.6δ (doublet, I=3), 3.6δ (sextet, I=1) Ans: Cl


9

1

73.

Propose a structure for a compound with molecular formula C8H14O3 that fits the following spectroscopic data. IR:1820cm-1, 1760cm-1 1H NMR: 1.0δ (triplet, I=6), 1.6δ (sextet, I=4), 2.2δ (triplet, I=4) Ans:

O

OO


74.

Propose a structure for a compound with molecular formula C10H12O that fits the following spectroscopic data. IR:1680cm-1 1H NMR: 1.0δ (triplet, I=3), 1.5δ (sextet, I=2), 2.6δ (triplet, I=4), 7.4δ (triplet, I=2), 7.5δ (triplet, I=1), 7.9δ (doublet, I=2) Ans: O


75.

A compound with a molecular formula C8H16O has the following 1H NMR spectrum. Provide a structure that is consistent with this spectrum?

Ans: O


0 1 2 PPM

1

2 2 2

6

3

76.

A compound with a molecular formula C10H12O2 has the following HNMR spectrum. Which of the following structures is consistent with this spectrum?

CH

O

O

O

O

COH

O

COH

O

I

II III IV


Ans: C Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Easy

0 1 2 3 4 5 6 7 8 9 10 11 PPM

1

2 2 2 2 3

77.

How many signals would you expect to find in the 13C NMR spectrum of the following compound?

O


Ans: B Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Easy

78.


OO


Ans: C Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Medium

79.



Ans: D Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Medium

80.

How many signals would you expect to find in the 13C NMR spectrum of the following compounds?

O

O

Cl

CH2CH3I II A) I-5, II-8 B) I-3, II-6 C) I-4, II-8 D) I-5, II-6 E) none of these

Ans: D Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Easy

81.

Which of the following carbon atoms will display the signal most downfield in the 13C NMR spectrum?

C NC

O

C C

F

C C

I II III IV V A) I B) II C) III D) IV E) none of these

Ans: B Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Medium

82.

Which of the following compounds will display four signals in the 13C NMR spectrum?

A) 2,6-dimethylheptane B) 2,4-dimethylheptane C) 3,5-dimethylheptane D) 4,4-dimethylheptane E) none of these

Ans: A Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Medium

83.

Which of the following compounds will display five signals in the 13C NMR spectrum? Br

Br

Br

Br

Br

Br

Br

BrI II III IV


Ans: A Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Medium

84.

Which of the following 13C NMR chemical shifts corresponds to Ca in the following compound?

O

a

A) 120 ppm B) 145 ppm C) 159 ppm D) 200 ppm E) none of these

Ans: C Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Hard

85.

Which of the following compounds is consistent with the following 13C NMR spectrum?

020406080100120140160180200PPM

O

O O

O

I II III IV


Ans: A Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Hard

86.


01020304050607080PPM

OH

HO

OH

I IIIII OH

IV


Ans: D Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Hard

87.


0102030405060PPM

Cl

Cl Cl

I II III A) I B) II C) III D) none of these

Ans: C Topic: 13C NMR spectroscopy Section: 16.11 & 16.12 Difficulty Level: Hard

88.


01020304050607080PPM

OH

HO

OH

I II IIIOH

IV


Ans: C Topic: DEPT 13C NMR spectroscopy Section: 16.13 Difficulty Level: Easy

89.

Which of the following display a signal in the DEPT-90 13C NMR spectroscopy?

A) CH3 B) CH2 C) CH D) C E) none of these

Ans: C Topic: DEPT 13C NMR spectroscopy Section: 16.13 Difficulty Level: Easy

90.

Which of the following displays a negative signal in the DEPT-135 13C NMR spectroscopy?


Ans: B Topic: DEPT 13C NMR spectroscopy Section: 16.13 Difficulty Level: Easy

91.

Which of the following does not display a signal in the DEPT-135 13C NMR spectroscopy?


Ans: D Topic: DEPT 13C NMR spectroscopy Section: 16.13 Difficulty Level: Medium

92.

Which of the following compounds will not display a carbonyl carbon signal in the DEPT-90 and DEPT-135 13C NMR spectroscopy?

H

O

O

O

NH

O

I II III A) I B) II C) III D) II & III E) none of these

Ans: D Topic: DEPT 13C NMR spectroscopy Section: 16.13 Difficulty Level: Medium

93.

A compound with molecular formula C5H10Br2 displays the following 13C NMR along with the DEPT-90 and DEPT-135 13CNMR spectrum. What is the structure for this compound?

Ans: BrCH2CH2CH2CH2CH2Br

Topic: DEPT 13C NMR spectroscopy Section: 16.13 Difficulty Level: Hard

94.

A compound with molecular formula C7H7Br displays the following 13C NMR along with the DEPT-90 and DEPT-135 13CNMR spectrum. What is the structure for this compound?

Ans:

Br

DEPT-90

DEPT-135

DEPT-90

DEPT-135

Broadband decoupled

Broadband decoupled

Topic: Integrated Spectroscopy Section: 15.6, 16.10, 16.12 Difficulty Level: Medium

95.

A compound with molecular formula C11H14O displays the following IR, 1HNMR and 13CNMR spectrum. Propose a structure for this compound.

020406080100120140160180200220PPM

Three spectra above: courtesy of SDBS: National Institute of Advanced Industrial Science and Technology Ans: O

Topic: Integrated Spectroscopy Section: 15.6, 16.10, 16.12

Difficulty Level: Medium

96.

A compound with molecular formula C7H14O2 displays the following IR, 1HNMR and 13CNMR spectrum. Propose a structure for this compound.

020406080100120140160180PPM

Three spectra above: courtesy of SDBS: National Institute of Advanced Industrial Science and Technology Ans:

O

O

Topic: Integrated Spectroscopy

1 2 2

6

3

Section: 15.6, 16.10, 16.12 Difficulty Level: Hard

97.

A compound with molecular formula C5H7NO2 displays the following IR, 1HNMR and 13CNMR spectrum. Propose a structure for this compound.



SDBS: National Institute of Advanced Industrial Science and Technology Ans:

O

O

CN



98.

Propose a structure for a compound with molecular formula C5H10O that fits the following spectroscopic data. IR:1720cm-1 1H NMR: 1.1δ (doublet, I=6), 2.1δ (singet, I=3), 2.7δ (septet, I=1) 13C NMR: 15, 22, 45, 210 Ans:

O Topic: Integrated Spectroscopy Section: 15.6, 16.10, 16.12 Difficulty Level: Medium

99.

Propose a structure for a compound with molecular formula C8H19N that fits the following spectroscopic data. IR: 3400cm-1 1H NMR: 0.9δ (triplet, I=6), 1.1δ (singlet, I=1, exchanges with D2O), 1.3δ (sextet, I=4), 1.4δ (quintet, I=4), 2.6δ (triplet, I=4) 13C NMR: 13.7, 20.5, 30.4, 49.2 Ans:

NH

Topic: Integrated Spectroscopy Section: 15.6, 16.10, 16.12 Difficulty Level: Hard

100.

Propose a structure for a compound with molecular formula C5H12O2 that fits the following spectroscopic data. IR: 1200cm-1 1H NMR: 1.4δ (singlet, I=6), 3.2δ (singlet, I=6) 13C NMR: 28, 45, 100 Ans:

OO


Difficulty Level: Hard

101.

Propose a structure for a compound with molecular formula C6H10O that fits the following spectroscopic data. IR: 3400 cm-1(broad), 3250 cm-1(sharp), 2150 cm-1 1H NMR: 1.0δ (triplet, I=3), 1.5δ (singlet, I=3), 1.6δ (quartet, I=2), 2.5δ (singlet, I=1), 3.4δ (singlet, I=1) 13C NMR: 5, 26, 35, 67, 69 Ans: OH

Topic: Integrated Spectroscopy Section: 15.6, 16.10, 16.12 Difficulty Level: Hard

102.

Propose a structure for a compound with molecular formula C8H15ClO3 that fits the following spectroscopic data. IR: 1780 cm-1, 1150 cm-1

1H NMR: 1.1δ (triplet, I=6), 1.9δ (quartet, I=2), 2.8δ (triplet, I=2), 3.4δ (quartet, I=4), 4.2δ (triplet, I=1) 13C NMR: 15, 31, 38, 57, 100, 173 Ans:

O

O

Cl

O

Topic: Integrated Spectroscopy Section: 15.6, 16.10, 16.12 & 16.13


103.

A compound with molecular formula C3H6O2 displays the following IR, 1HNMR and 13CNMR spectrum. Propose a structure for this compound.

Ans:

OH

O


DEPT-90

DEPT-135

Broadband decoupled

Section: 15.6, 16.10, 16.12 & 16.13 Difficulty Level: Medium

104.

A compound with molecular formula C6H12O displays the following IR, 1HNMR and 13CNMR spectrum. Propose a structure for this compound.

Ans:

O


DEPT-135

1

DEPT-90

Broadband decoupled

Section: 15.6, 16.10, 16.12 & 16.13 Difficulty Level: Hard

105.

A compound with molecular formula C6H4Cl2O displays the following IR, 1HNMR and 13CNMR spectrum. Propose a structure for this compound.

Ans:

OH

Cl

Cl

DEPT-90

DEPT-135

Broadband decoupled

ch16-ques-2013

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d topic

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