Download - Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Transcript
Page 1: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

1

3.1(a) 1,2,3,4 are a spin system. Pople notation is A3M2S2X2. 1,2, and 3 are enantiotopic. 3.2 (a)

Spin Appr. δ Table Coupled with Multiplet (n+1) Integration 1 δ 3.40 Appendix A, Chart A.1 2 Triplet 2 2 δ 1.85 Appendix A, Chart A.2 1,3 Quintet 2 3 δ 1.20 Appendix A, Chart A.1 3, 4 Sextet 2 4 δ 0.85 Appendix A, Chart A.1 3 Triplet 3

3.3 (a)

Br

(a) 1-bromobutane

12

34

1 2 3 4

Page 2: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

2

3.1 (b) 1,2,3,4,5,6,7 are one spin system, and 9 is the second. 4,4’ ; 5,5’ ; 6,6’and 7,7’ are diastereotopic. 3.2 (b)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 δ 2.80 Appendix A, Chart A.2 6,2,7 Sextet* 1 2 δ 5.59 Appendix D, Chart D2 3,1 Triplet* 1 3 δ 5.59 Appendix D, Chart D2 Quartet* 1 4 δ 1.96 Appendix D, Chart D2 Quartet** 2 5 δ 1.65 Appendix D, Chart D2 4,6 Quartet** 2 6 δ 1.80 Appendix A, Chart A.2 1,5 Triplet** 2 7 δ 4.05 Appendix A, Chart A.2 1 Doublet** 2 9 δ 2.10 Appendix A, Chart A.1 none Singlet 3

* Coupling constants may not be the same, but make the assumption that they are. **These are diastereotopic, and are coupled to diastereotopic protons, they would not be first order. We will assume they are first order for the drawn spectrum. 3.3 (b)

2 and 3 7 1 9 4 6 5

O

1

23

4

5 6

7O

8 9

(b) (cyclohex-2-enyl)methyl acetate

2

Page 3: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

3

3.1 (c) 2,3,4,5,6 are a spin system, and 8,9,10 another spin system. 3,3’ ; 4,4’ ; 9,9’ are diastereotopic. 3.2 (c)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 2 δ 6.68 Appendix D, Chart D.1 3 Triplet 1 3 δ 2.05 Appendix A, Chart A1 2,4 Quartet*** 2 4 δ 2.05 Appendix A, Chart A1 3,5 Quartet*** 2 5 δ 5.68 Appendix D, Chart D1 4,6 Quartet* 1 6 δ 6.22 Appendix D, Chart D1 5 Doublet 1 8 δ 2.65 Appendix A, Chart A.1 9,10 Sextet 1 9 δ 3.20 Appendix A, Chart A.1 8 Doublet** 2 10 δ 1.05 Appendix A, Chart A.2 8 Doublet 3 ΟΗ δ 0.5-4.0 Appendix E 1

* Coupling constants may not be the same, but make the assumption that they are. ** These are diastereotopic, and are coupled to diastereotopic protons; they would not be first order. We will assume they are first order for the drawn spectrum. 3.3 (c)

OH

O

12

3

45

6

78

(c) 1-(cyclohexa-1,5-dienyl)-3-hydroxy-2-methylpropan-1-one

9

10

2 6 5 9 8 3,4 OH 10

Page 4: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

4

3.1 (d) 5,4,3 are a spin system and 1 is second. 5,4,3 is Pople notation is A3M2X2; may have long rang coupling. 3+4 are enantiotopic. 3.2 (d)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 5 δ 0.85 Appendix A, Chart A.2 4 Triplet 3 4 δ 1.50 Appendix A, Chart A2 3,5 Sextet 2 3 δ 2.20 Appendix A, Chart A1 4 Triplet 2 1 δ 1.80 Appendix D, Chart D3 none Singlet 1

3.3 (d)

H

(d) pent-1-yne

13 24

5

3 1 4 5

Page 5: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

5

3.1 (e) 3,4,5,6 are a spin system, and 1 is another spin system. Pople notation is A3G2MX. 5 is enantiotopic. 3.2 (e)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 δ 1.86 Appendix D, Chart D.2 None Singlet 3 3 δ 6.09 Appendix D, Chart D.1 4 Doublet 1 4 δ 6.82 Appendix D, Chart D.1 3, 5 Quartet* 1 5 δ 2.05 Appendix A, Chart A1 4, 6 Quintet* 2 6 δ 1.00 Appendix A, Chart A2 5 Triplet 3

* Coupling constants may not be the same, but make the assumption that they are. 3.3 (e)

4 3 5 1 6

O

(e) hex-3-en-2-one

1 34

52 6

Page 6: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

6

O

(f) 1-methoxybut-1-ene

1 23

45

3.1 (f) 3,4,5,6 are a spin system, and 1 is another spin system. Pople notation is A3G2MX. 4 is enantiotopic. 3.2 (f)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 δ 3.20 Appendix A, Chart A.1 None Singlet 3 2 δ 6.14 Appendix D, Chart D.1 3 Doublet 1 3 δ 4.63 Appendix D, Chart D.1 2, 4 Quartet* 1 4 δ 2.05 Appendix A, Chart A1 3, 5 Quintet* 2 5 δ 1.00 Appendix A, Chart A2 4 Triplet 3

* Coupling constants may not be the same, but make the assumption that they are. 3.3 (f)

2 3 1 4 5

Page 7: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

7

NH

O

O

(g) propyl methylcarbamate

1

2 34

5

3.1 (g) 3,4,5 are a spin system, and 1 is another spin system. Pople notation is A3M2X2. 3 and 4 are enantiotopic. 3.2 (g)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 δ 2.95 Appendix A, Chart A.1 None Singlet 3 3 δ 4.10 Appendix D, Chart D.1 3 Triplet 2 4 δ 1.60 Appendix A, Chart A.2 2, 4 Sextet 2 5 δ 0.85 Appendix A, Chart A1 3, 5 Triplet 3

NH δ 4.5-7.5 Appendix E * Singlet 1 *See Section 3.6.2 for coupling between 1 and N-H. 3.3 (g)

NH 3 1 4 5

Page 8: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

8

O O

(h) diethoxymethane

12 3

3.1 (h) 1 and 2 are a spin system, and 3 is another spin system. Pople notation is A3X2. 2 are enantiotopic. 3.2 (h)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 δ 1.20 Appendix A, Chart A.2 2 Triplet 3 2 δ 3.40 Appendix A, Chart A.1 1 Quartet 2 3 δ 4.95 Appendix B, Table B.1 none Singlet 2

3.3 (h)

3 2 1

Page 9: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

9

HO

(i) 2-methylpentan-2-ol

1

23

45

6

1 and 6 Large singlet of 6 H

3.1 (i) 3,4 and 5 is a spin system. 1 and 6 are enantiotopic to each other and 3 and 4 are also enantiotopic. Pople notation is A3M2X2. 3.2 (i)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 and 6 δ 1.20 Appendix A, Chart A2 none Singlet 6

3 δ 1.50 Appendix A, Chart A2 4 Triplet 2 4 δ 1.20 Appendix A, Chart A1 3,5 Sextet 2 5 δ 0.85 Appendix A, Chart A2 4 Triplet 3

ΟΗ δ 0.5-4.0 Appendix E none Singlet 1 3.3 (i)

OH 3 1,6,4

Page 10: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

10

SS

(j) 1,4-bis(methylthio)butane

1 23

3.1 (j) Not First order (no Pople). See Section 3.11.2. Protons 2 and 3 are enantiotopic. Protons on 1,2,3 are Chemical Shift Equivalent. 3.2 (j)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 δ 2.10 Appendix A, Chart A1 none Singlet 6 or 3 2 δ 2.60 Appendix A, Chart A1 3 Triplet* 4 or 2 3 δ 1.60 Appendix A, Chart A2 2,3 Quintet* 4 or 2

* Would not be first order. We will assume they are first order for the drawn spectrum. 3.3 (j) Actual spectrum would look like this!

012PPM

Page 11: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

11

N

O

(k) N,N,4-trimethylbenzamide

1

2

3

4

5

6

78

2'3'

3.1 (k) 2,2’; 3,3’ are CSE but not ME. 6 and7 are diastereotopic. Pople notation for ring is AA’ XX’ 3.2 (k)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 2, 2’ δ 7.80 Appendix D, Chart D1 none Doublet** 2 3, 3’ δ 7.25 Appendix D, Chart D1 3 Doublet** 2 6,7 δ 2.95 Appendix A, Chart A1 none Singlet* 6* 8 δ 2.25 Appendix A, Chart A1 none Singlet 3

* There will be two singlets because of the restricted rotation of the NR2 ** These can not be first order. Not magnetically equivalent. 3.3 (k)

2,2’ 3,3’ 6,7 8

Page 12: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

12

O

OH(l) 1-(2-hydroxyphenyl)ethanone

1

2

34

5

6

78

3.1 (i) N.A. 3.2 (i)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 3 δ 6.85 Appendix D, Chart D.1 4 Doublet* 1 4 δ 7.05 Appendix D, Chart D.1 3,5 Triplet* 1 5 δ 7.25 Appendix D, Chart D.1 4,6 Triplet* 1 6 δ 7.70 Appendix D, Chart D.1 5 Doublet* 1 8 δ 2.40 Appendix A, Chart A1 none Singlet 3

OH δ 5.5-12.5 Appendix E none Singlet 1 * Will have long range coupling. 3.3 (i) OH 6 5 4 3 8

Page 13: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

13

ClH

O(m) 2-chloroacetaldehyde

12

3.1(m) 1 and 2 is a spin system. Pople notation is A2X. 2 protons are enantiotopic. 3.2 (m)

Spin Appr. δ Table Coupled with Multiplet (n+1) Integration 1 δ 4.95 Appendix A, Chart A.1

Plus Appendix B, Table B.1* 2 Triplet 1

2 δ 9.80 Appendix D, Chart D.6 extrapolation

1 Doublet 2

Calc is based on Chart A1 3.45 for ClCH2 plus Table B.1 value of 1.50 for HC=O 3.3 (m)

2 1

Page 14: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

14

HH

H

F(n) fluoroethene

1

23

Protocol of the H-1 NMR Prediction:

Node Shift Base + Inc. Comment (ppm rel. to TMS)

H 4.85 5.25 1-ethylene -0.40 1 -F cis H 6.79 5.25 1-ethylene 1.54 1 -F gem H 4.23 5.25 1-ethylene -1.02 1 -F trans

01234567PPM

3.1(n) Charts are not available in text for this problem. Pople notation is AGMX, where X is F. 3.2 (n) 3.3 (n)

Page 15: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.1 to 3.3

15

O

(o) cyclohexyl acetate

O1

2

34

5

6

2'3'

3.1 (o) 1,2,2’,3,3’, and 4 is a spin system, and 6 is another spin system. 2,2,;2’,2’;3,3;3’,3’;4,4 protons are diastereotopic. 2 and 2’ are CSE, also 3 and 3’ are CSE. 3.2 (o)

Spin Appr. δ Table or Calculation Coupled with Multiplet (n+1) Integration 1 δ 4.95 Appendix A, Chart A.1 2,2’ Quintet 1

2,2’ δ 1.60 Appendix A, Chart A.2 1,(3or3’) Quartet* 4 3,3’ δ 1.44 Appendix C, Table C.1 (2 or 2’),4 Quintet* 4

4 δ 1.44 Appendix C, Table C.1 3,3’ Quintet* 2 6 δ 2.00 Appendix A, Chart A.1 none Singlet 3

* These are diastereotopic, and are coupled to diastereotopic protons; they would not be first order. We will assume they are first order for the drawn spectrum. 3.3 (o)

1 6 2,2’ 3,3’, and 4

4

Page 16: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.4 16

0.80.91.01.11.21.31.41.51.61.71.81.92.02.12.22.32.42.5 ppm

Problem 4.3 A C7H14O

Problem 4.3 B C7H16O

0.80.91.01.11.21.31.41.51.61.71.81.92.02.12.22.32.42.5 ppm

1.01.52.02.53.03.54.0 ppm

2.53.03.54.04.55.05.56.06.57.07.5 ppm

1.01.52.02.53.03.5 ppm

Problem 4.3 C C7H7Br

Problem 4.3 D C5H11Br

OH

Problem 3.4 A

Problem 3.4 D

Problem 3.4 C

Problem 3.4 B

O

4-Heptanone

1 23

4

OH

3-Heptanol

1 23 4 5 6

7

Br

4-Bromotoluene

1

2 3

45

Br

2-Bromopentane

1 23

45

1

2 3

1

7 6

2 4

5 3

2

5

3

1

2

4

5

3

Page 17: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.4 17

0.80.91.01.11.21.31.41.51.61.71.81.92.02.12.22.32.42.5 ppm

2.02.22.42.62.83.03.23.43.63.84.04.24.4 ppm

0.80.91.01.11.21.31.41.51.61.71.81.92.02.12.22.32.42.52.62.7 ppm

1.52.02.53.03.5 ppm

Problem 4.3 E C6H12O

Problem 4.3 F C3H6O2

Problem 4.3 G C4H11N

Problem 4.3 H C3H4O

11.512.0 ppm

x4

Problem 3.4 E

Problem 33.4 H

Problem 3.4 G

Problem 3.4 F

1 23

45 6

O

2-Hexanone

12

3

O

HOPropionic Acid

12

34

H2N

Butylamine

1 23

OH

Propargyl alcohol

1

6

4 5 3

2

3

OH

1 OH 3

1

2

4

3

NH2

Page 18: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.4 18

1.01.52.02.53.03.54.04.5 ppm

1.01.52.02.53.03.5 ppm

1.52.02.53.03.54.04.55.05.56.06.57.07.5 ppm

2.02.53.03.54.04.55.05.56.06.57.07.5 ppm

Problem 4.3 I C3H7NO2

Problem 4.3 J C8H10O2

Problem 4.3 K C8H10O

Problem 4.3 L C5H10O2

210021502200 Hz 115012001250 Hz

Problem 3.4 I

Problem 3.4 L

Problem 3.4 K

Problem 3.4 J

N+

O

-O1-Nitropropane

1 2 3

46

O

OH

2-Phenoxylethanol

1

23

5

45

6

O

Phenetole

12 3

5

OO

Methyl Butyrate

1 2 34

6

2 4

5

3

2 4

5 3

6 2

4

5

3

OH

1 2

3

Page 19: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.4 19

1.52.02.53.03.54.04.55.05.56.06.57.0 ppm

7.37.47.57.67.77.87.98.08.18.2 ppm

4.04.55.05.56.06.57.07.5 ppm

3.03.54.04.55.05.56.06.57.07.58.08.5 ppm

2490250025102520 Hz

Problem 4.3 M C6H11NO

Problem 4.3 N C5H6N2 A pyrazine

Problem 4.3 O C8H8O3

Problem 4.3 P C6H4ClNO2

2150220022502300 Hz

1213 ppm

1 proton (x32)

Problem 3.4 M

Problem 3.4 P

Problem 3.4 O

Problem 3.4 N a pyrazine

56

O

HN

Caprolactam

1 23

4

6

7

N

N

2-methylpyrazine1

2

3 4

5

6

7

HOO

O

Methyl salicylate

1

2

3 4

5

8

N+O

-OCl

1-Chloro-4-Nitrobenzene

1

23

4

7

6

5

3

6

4

5 3 8

OH

2 3

6

2 4

5 3

NH

Page 20: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.4 20

1.52.02.53.03.54.04.5 ppm

1.01.21.41.61.82.02.22.42.62.8 ppm

1.52.02.53.03.54.04.55.0 ppm

1.61.82.02.22.42.62.83.03.23.43.6 ppm

150015101520 Hz

1112 ppm

1 proton (x32)

Problem 4.3 R C6H10O Unsaturated alcohol

Problem 4.3 Q C7H13BrO2 Acid

Problem 4.3 S C8H14O Unsaturated ketone

Problem 4.3 T C6H12O2

1213 ppm

Problem 3.4 Q

Problem 3.4 T

Problem 3.4 S Unsaturated ketone

Problem 3.4 R

7

O

HO Br7-Bromo Heptanoic Acid

12 3 4

5 6

HO5-Hexyn-1-ol

52

341

6

7

8O

6-Methyl-5-hepten-2-one2

341 5

6

O

HOHexanoic acid

342

1 5 6

6

2

4 5

3

OH

1

7

4

5

3

8

1

6

2 4

3 OH

7

6 2

5 4 3

OH

Page 21: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercise 3.4 21

5.75.85.96.06.16.26.36.46.56.66.76.86.97.07.17.27.37.47.5 ppm

2.02.53.03.54.04.55.05.56.06.57.0 ppm

2.53.03.54.04.55.05.56.06.57.0 ppm

Problem 4.3 W C6H8O Unsaturated ketone

Problem 4.3 V C8H10O

Problem 4.3 U C6H4OCl2

2060208021002120 Hz

Problem 3.4 U

Problem 3.4 W Unsaturated ketone

Problem 3.4 V

Cl

ClHO

2,6-Dichlorophenol

1

3

4

2

5HO

2,6-Dimethylphenol

3

4

1 2

O

2-Cyclohexen-1-one

34

12

5

6

6

2

4 5

3

4

3

5

OH

4

3 OH

Page 22: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

22

3.5A. (1.58(300) – 0.90(300))/7 = about 29; (2.36(300) – 1.58(300))/7 = about 33 3.5E. (2.38(300) – 1.52(300))/7 = about 37; (1.52(300) – 1.38(300))/7 = about 6 (1.38(300) – 0.87(300))/7 = about 22 3.5F. (2.38(300) – 1.13(300))/7 = about 54 3.5G. (2.61(300) – 1.35(300))/7 = about 54; (1.35(300) – 1.29(300))/7 = about 2 to 3 (1.29(300) – 0.84(300))/7 = about 19 3.5H. Long range coupling; can’t measure coupling constant 3.5I. (4.33(300) – 2.01(300))/7 = about 99; (2.01(300) – 0.99(300))/7 = about 44 3.5K. (4.08(300) – 1.44(300))/7 = about 113 3.5L. (2.26(300) – 1.62(300))/7 = about 27; (1.62(300) – 0.92(300))/7 = about 30 3.5Q. (3.39(300) – 1.86(300))/7 = about 66; (2.36(300) – 1.65(300))/7 = about 30 (1.86(300) – 1.47(300))/7 = about 17; (1.65(300) – 1.37(300))/7 = about 12 3.5U. (7.25(300) – 6.81(300))/9 = about 15

Answers for Student Exercise 3.5

Page 23: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercises 3.6 23

O

4-Heptanone

A

1 23

4

Pople Notation -- A3M2X2; 2 and 3 (and 5 and 6) are enantiotopic. 3 and 5, 2 and 6 are CSE.

OH

3-Heptanol

B

1 23 4 5 6

7

One spin system. 2,2’; 4,4’; 5,5’, and 6,6’ are diastereotopic.

Br

4-Bromotoluene

C

1

2 3

45

Two spin systems. Pople Notation -- AA’XX’. 2 and 2’ are CSE but not magnetically equivalent as are 3 and 3’.

Br

2-Bromopentane

D

1 23

45

One spin system. 3 and 3’; 4 and 4’ are diastereotopic.

1 23

45 6

O

2-Hexanone

E Two spin systems. 3, 4, and 5 are enantiotopic.

12

3

O

HOPropionic Acid

F A3X2. Protons on two are enantiotopic.

Page 24: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercises 3.6 24

12

34

H2N

Butylamine

G Pople Notation – A3G2M2X2One spin system. 1, 2, and 3 are enantiotopic.

1 23

OH

Propargyl alcohol

H One spin system with long range coupling. Protons on 2 enantiotopic.

N+

O

-O1-Nitropropane

I

1 2 3

Pople Notation -- A3M2X2. 1 and 2 are enantiotopic.

46

O

OH

2-Phenoxylethanol

J

1

23

5

2'3'

Two spins systems; Pople Notation -- AA’MM’X and A2X2. 2 and 2’are CSE but not magnetically equivalent as are 3 and 3’. 5 and 6 are enantiotopic.

45

6

O

Phenetole

K

12 3

2' 3'

Two spins systems; Pople Notation -- AA’MM’X and A3X2. 2 and 2’are CSE but not magnetically equivalent as are 3 and 3’. 5 and 6 are enantiotopic.

5

OO

Methyl Butyrate

L

1 2 34

Two spin systems; Pople Notation --A3M2X2. 2 and 3 are enantiotopic.

Page 25: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercises 3.6 25

56

O

HN

Caprolactam

M

1 23

4

One spin system. 2,2’; 3,3’; 4,4’; 5,5’ and 6,6’ are diastereotopic.

6

7

N

N

2-methylpyrazine

N

1

2

3 4

5

Pople Notation –AB for 5 and 6. Three spins systems.

6

7

HOO

O

Methyl salicylate

O

1

2

3 4

5

8

Two spin systems. Pople Notation – AGMX.

N+O

-OCl

1-Chloro-4-Nitrobenzene

P

1

23

4

3' 2'

One spin system. 2 and 2’ are CSE but not magnetically equivalent as are 3 and 3’.

7

O

HO Br7-Bromo Heptanoic Acid

Q

12 3 4

5 6

One spin system. 2, 3, 4, 5, 6, and 7 are enantiotopic.

Page 26: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

Answers for Student Exercises 3.6 26

HO5-Hexyn-1-ol

R

52

341

6

One spin system with long range coupling. 1, 2, 3, and 4 are enantiotopic.

7

8O

6-Methyl-5-hepten-2-one

S

23

41 56

At 2 spins systems (7 and 8 probably have long range coupling). 3 and 4 are enantiotopic.

O

HOHexanoic acid

T

342

1 5 6

One spin system. 2, 3, 4, and 5 are enantiotopic.

Cl

ClHO

2,6-Dichlorophenol

U

1

3

4

2

3'

One spin system. 3 and 3’ are CSE but not magnetically equivalent.

5HO

2,6-DimethylphenolV

3

4

1 26

3'

One spin system. 3 and 3’ are CSE but not magnetically equivalent. 5 and 6 are CSE.

O

2-Cyclohexen-1-one

W

34

12

5

6

One spin system. 4, 5, and 6 are enantiotopic.

Page 27: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

27Answers for Student Exercise 3.7

JAX

AX

A2X

A3X

11

11

1 2 1

11

1 3 3 1

1 2 1

JXA

11

JAX

11

JXA

XA

JXA

JAX

11

A2X2

11

1 2 1

11

1 2 1

A3X2

11

1 2 1

JAX

JAX

11

1 3 3 1

1 2 1

JXA

JXA

A X

A2 X

A3

X

A2 X2

A3

X2

Page 28: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

28Answers for Student Exercise 3.8

JAM

JAM

JMX

AMX

A2MX

A3MX

11

11

JMX

11

1 2 1

JAM

JMX

11

1 3 3 1

1 2 1

JAM

JMX

11

1 3 3 1

1 2 1

1 4 6 4 1

A M X

A2 M X

A3 M X

With the AMX systems A and X do not change; they are represented as follows:

Page 29: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

29Answers for Student Exercise 3.8 Continued

A2MX2

JAM

JMX

11

1 3 3 1

1 2 1

1 4 6 4 1

A2MX3

JAM

JMX

11

1 3 3 1

1 2 1

1 4 6 4 1

1 5 10 10 5 1

JAM

JMX

11

1 3 3 1

1 2 1

1 4 6 4 1

1 5 10 10 5 1

A3MX3

1 6 15 20 15 6 1

A2 M X2

A2

M

X3

A3 M X3

Page 30: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

30Answers for Student Exercise 3.9

JAM

JAM

JMX

JMX

AMX

A2MXJAM

JAM

1 1 1

11 11

11

1

2 2

A3MX

1 3 3 1

1 1

1 12

JMX1 1 1 13 3 3 3

1 12

1 1

11

11

JMX

With the AMX systems A and X do not change; they are represented as follows:

The following are for M:

Page 31: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

31Answers for Student Exercise 3.9 Continued

A2MX3 JAM

11 11 2 2

1 12

1 1

JMX

1 2 3 4 3 2 1

3 5 7 7 5 3 1

JAMA3MX3

1

1 3 3 1

1 1

1 12

JMX1 1 1 13 3 3 3

2 4 6 6 6 4 2 1

1 3 6 10 12 12 10 6 3 1

A2MX2 JAM

11 11 2 2

1 1

1 2 3 4 3 2 1

1 12

JMX

1

Page 32: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

32Answers for Student Exercise 3.10A

Jca

11

1 2 1 Jcb

1 1 2 2 1 1

(c)

Spin System ab2c3Couplinga-b 6 Hzb-c 12Hza-c 3 Hz

11

1 2 1

Jbc

Jba

1 3 3 1

1 1 3 3 3 3 1 1(b)

Jab

1 1

1 2 1

1 1 2 2 1 1

1

1

2 3 4 3 2 1

3 5 7 7 5 3 1

Jac(a)

Page 33: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

33

Jcb

Jca

(c)

Spin System ab2c3Couplinga-b 6 Hzb-c 4Hza-c 9 Hz

Jbc

Jba

(b)

Jab

Jac(a)

1 1

1 1 1 1

1 2 1 1 2 1

1 1

1 1 1 1

1

1 1

12 11 2

3 1 3 3 1 3

1 1

1

1

1

1

2 1

3 3 1

1 3 3 3 3 1 1

2 3 1 6 3 3 6 1 3 2 1

Answers for Student Exercise 3.10B

Page 34: Answers for Student Exercise 3.1 to 3.3 1 - NTNUfolk.ntnu.no/audunfor/6. semester/Spektroskopi/solutions_NMR_ch03.pdf · Answers for Student Exercise 3.1 to 3.3 5 3.1 (e) 3,4,5,6

34Answers for Student Exercise 3.10C

Jcb

Jca

(c)

Spin System a2b2c2Couplinga-b 6 Hzb-c 4Hza-c 9 Hz

Jbc

Jba

(b)

Jab

Jac

(a)

1

1

1

1 1

1

1

21 41

1

2

1

4

11

1 2

2

22

22

1

1

1

1

1

1

1

11

1 2

2

2

2

22 241 1

1

1

1

1

1

1

1

1

1

1

2

2

2

2

2 2