Homework Answers
Spectroscopy:
• Nuclear magnetic resonance
spectroscopy is one of the techniques in analytical chemistry that is widely used to determine the purity of sample and also to predict the structure of the organic compounds.
• The 
spectroscopy is phenomenon that is observed when frequency of nuclei of atoms (sample) resonates with frequency of rotating magnetic field.
• Spectroscopy provides the information about the identification of carbon atoms in an organic molecule. It is analogous to the proton NMR spectroscopy, identifies carbon atoms and elucidation of chemical structure. .
Chemical Shift
:
• The relative difference between the frequency of absorbed electromagnetic radiation by the sample and the frequency of absorbed electromagnetic radiation by the standard usually TMS divided by the spectrometer operating frequency.
• It is expressed in parts per million (ppm).
Mathematical equation for the chemical shift:
The frequency of absorbed radiation by the sample is
.
The frequency of absorbed radiation by the standard is
.
The following figures give the representation of chemical shift for and the reference standard is tetramethylsilane (TMS).
Alkanes Alkyl halides |
Alkynes |
Alkenes |
Esters amides |
aldehyde ketone |
Ketone Aldehyde | Esters Amides | Alkenes | Alkynes | Alkanes Alkyl halides |
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Sort the following compound classes into the bins corresponding to the expected ^13C chemical shifts (ppm)....
12 POV Chemical shifts: Singlet at 11.8 ppm, triplet at 2.20 ppm, multiplet at 1.46 ppm,...
12 POV Chemical shifts: Singlet at 11.8 ppm, triplet at 2.20 ppm, multiplet at 1.46 ppm, multiplet at 1.22 pm, triplet at 0.78 ppm What is the structural formula of the compound with molecular formula CsH10O2 that corresponds to the 1H spectrum above? Select one: a. (CH3)3CCOOH ob. CH3(CH2)2COOH C. (CH3)2CHCH2COOH
Question 20 Determine the multiplicity and predict the chemical shifts of each signal in the expected...
Question 20 Determine the multiplicity and predict the chemical shifts of each signal in the expected 'H NMR spectrum of the following compound. V O III IV VI II 1 - ppm II - ppm, ppm, IV - ppm, V- ppm VI - ppm,
Chemical shifts: Singlet at 3.19 ppm, singlet at 0.89 ppm What is the structural formula for...
Chemical shifts: Singlet at 3.19 ppm, singlet at 0.89 ppm What is the structural formula for the compound with molecular formula CsHCl that corresponds to the 1H NMR spectrum above? Select one: O a. CH(CH2)4CI b. (CH),CCHCI C. (CH3),CHCHCICH
Compound E, chemical formula C5H10O2 , is a volatile liquid (boiling point 88°C). The 13C-NMR spectrum...
Compound E, chemical formula C5H10O2 , is a volatile liquid
(boiling point 88°C). The 13C-NMR spectrum shows signals
at ? 171.0, 68.3, 23.0, and 17.6 ppm. The predicted
1H-NMR spectrum is shown, propose a structure for
compound E.
Compound E, chemical formula C5H1002. is a volatile liquid (boiling point 88°C . The 13C NMR spectrum shows signals at ppm. The predicted 'H-NMR spectrum is shown, propose a structure for compound E. 1710, 68.3, 23.0, and 17.6 3H 6H 1H PPM...
6. A compound with the molecular formula of C4H2O2 shows TH NMR as below. Its 13C...
6. A compound with the molecular formula of C4H2O2 shows TH NMR as below. Its 13C NMR peaks appear at the following chemical shifts: d 161, 65, 22, 10. Give the most plausible structure in the box. АР 3H 2H 2H PPM Your answer here.
draw the compound and assign the peaks to it 8 19 31 176 00 350 089 05769 8 10 ppm spectrum and clearly assign the chemical shifts to the appropriate protons on the molecule 8 19 31 1...
draw the compound and assign the peaks to it
8 19 31 176 00 350 089 05769 8 10 ppm spectrum and clearly assign the chemical shifts to the appropriate protons on the molecule
8 19 31 176 00 350 089 05769 8 10 ppm
spectrum and clearly assign the chemical shifts to the appropriate protons on the molecule
38. Which of the following is a correct prediction of the chemical shifts for the signals...
38. Which of the following is a correct prediction of the chemical shifts for the signals in the 'H NMR spectrum for the following compound? 1 III A) 1-0.9 ppm, 11-1.7 ppm, III-3.9 ppm, IV-2.4 ppm B) 1-0.9 ppm, 11-1.2 ppm. III-3.7 ppm. IV-1.9 ppm C) 1-0.9 ppm, 11-1.7 ppm, 111-3.4 ppm, IV-2.4 ppm D) 1-0.9 ppm, 11-1.7 ppm, III-3.4 ppm, IV-1.9 ppm
Investigate the following IR Absorption, 13C and 1H NMR below: Compound X's IR (BELOW) Compound X's...
Investigate the following IR Absorption,
13C and 1H
NMR below:
Compound X's IR (BELOW)
Compound X's 13C NMR (BELOW)
Compound X's 1H NMR (BELOW)
1. Investigate the diagnostic IR
Absorption of compound X shown above and
use this to determine the functional groups
present. Use a table that goes (as an
example):
(EXAMPLE ONLY)
Frequency
(cm-1)
Relative Intensity or
Shape
Vibrational
Assignment
2950
Medium
C-H Stretch
1715
Sharp and Strong
C double bond O Stretch
2. Investigate the 1H and...
Draw the structure of the compound C10H12O that exhibits the 13C-NMR spectrum and DEPT data below. Impurity peaks are omitted from the DEPT data list. The triplet at 77 ppm is CDCl3. Draw the structu...
Draw the structure of the compound
C10H12O that exhibits the
13C-NMR spectrum and DEPT data below. Impurity peaks are
omitted from the DEPT data list. The triplet at 77 ppm is
CDCl3.
Draw the structure of the compound C10H120 that exhibits the 13C-NMR spectrum and DEPT data below. Impurity peaks are omitted from the DEPT data list. The triplet at 77 ppm is CDCl Used with p n from Aldrich Chemical Co., Inc. Solvent CDCls Shift DEPT 90 DEPT 135...
Which compound matches the following 13C NMR? 160 140 120 100 60 40 80 PPM NH2...
Which compound matches the following 13C NMR? 160 140 120 100 60 40 80 PPM NH2 A. B. C. D. H ОА OD Ос OB
12 POV Chemical shifts: Singlet at 11.8 ppm, triplet at 2.20 ppm, multiplet at 1.46 ppm, multiplet at 1.22 pm, triplet at 0.78 ppm What is the structural formula of the compound with molecular formula CsH10O2 that corresponds to the 1H spectrum above? Select one: a. (CH3)3CCOOH ob. CH3(CH2)2COOH C. (CH3)2CHCH2COOH
Question 20 Determine the multiplicity and predict the chemical shifts of each signal in the expected 'H NMR spectrum of the following compound. V O III IV VI II 1 - ppm II - ppm, ppm, IV - ppm, V- ppm VI - ppm,
Chemical shifts: Singlet at 3.19 ppm, singlet at 0.89 ppm What is the structural formula for the compound with molecular formula CsHCl that corresponds to the 1H NMR spectrum above? Select one: O a. CH(CH2)4CI b. (CH),CCHCI C. (CH3),CHCHCICH
Compound E, chemical formula C5H10O2 , is a volatile liquid
(boiling point 88°C). The 13C-NMR spectrum shows signals
at ? 171.0, 68.3, 23.0, and 17.6 ppm. The predicted
1H-NMR spectrum is shown, propose a structure for
compound E.
Compound E, chemical formula C5H1002. is a volatile liquid (boiling point 88°C . The 13C NMR spectrum shows signals at ppm. The predicted 'H-NMR spectrum is shown, propose a structure for compound E. 1710, 68.3, 23.0, and 17.6 3H 6H 1H PPM...
6. A compound with the molecular formula of C4H2O2 shows TH NMR as below. Its 13C NMR peaks appear at the following chemical shifts: d 161, 65, 22, 10. Give the most plausible structure in the box. АР 3H 2H 2H PPM Your answer here.
draw the compound and assign the peaks to it
8 19 31 176 00 350 089 05769 8 10 ppm spectrum and clearly assign the chemical shifts to the appropriate protons on the molecule
8 19 31 176 00 350 089 05769 8 10 ppm
spectrum and clearly assign the chemical shifts to the appropriate protons on the molecule
38. Which of the following is a correct prediction of the chemical shifts for the signals in the 'H NMR spectrum for the following compound? 1 III A) 1-0.9 ppm, 11-1.7 ppm, III-3.9 ppm, IV-2.4 ppm B) 1-0.9 ppm, 11-1.2 ppm. III-3.7 ppm. IV-1.9 ppm C) 1-0.9 ppm, 11-1.7 ppm, 111-3.4 ppm, IV-2.4 ppm D) 1-0.9 ppm, 11-1.7 ppm, III-3.4 ppm, IV-1.9 ppm
Investigate the following IR Absorption,
13C and 1H
NMR below:
Compound X's IR (BELOW)
Compound X's 13C NMR (BELOW)
Compound X's 1H NMR (BELOW)
1. Investigate the diagnostic IR
Absorption of compound X shown above and
use this to determine the functional groups
present. Use a table that goes (as an
example):
(EXAMPLE ONLY)
Frequency
(cm-1)
Relative Intensity or
Shape
Vibrational
Assignment
2950
Medium
C-H Stretch
1715
Sharp and Strong
C double bond O Stretch
2. Investigate the 1H and...
Draw the structure of the compound
C10H12O that exhibits the
13C-NMR spectrum and DEPT data below. Impurity peaks are
omitted from the DEPT data list. The triplet at 77 ppm is
CDCl3.
Draw the structure of the compound C10H120 that exhibits the 13C-NMR spectrum and DEPT data below. Impurity peaks are omitted from the DEPT data list. The triplet at 77 ppm is CDCl Used with p n from Aldrich Chemical Co., Inc. Solvent CDCls Shift DEPT 90 DEPT 135...
Which compound matches the following 13C NMR? 160 140 120 100 60 40 80 PPM NH2 A. B. C. D. H ОА OD Ос OB
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