Please help? And show work to help me understand? Characterization Use the infor

Question

Please help? And show work to help me understand?

Characterization Use the information provided below and the IR and NMR spectra on the next page to answer the following questions. 2. a) An MS was taken of molecule A and the table is given below. Determine the molecular formula of A from the MS given below. (Hint: There is at least one oxygen atom in this molecule abundance m/z (Intensity) 115 114 0.13 b) Calculate the Index of Hydrogen Deficiency (IHD) for the molecule in a, above. c) An IR spectrum of molecule A appears below. What functional group or groups correspond(s) to the labelled peaks (1662 cm and 1649 cm) in the spectrum? Draw the structure of this/these group(s), showing all bonds (i.e. single, double, triple). 1662 cm1 1649 cm 1662 1849 d) Using the information in a, b, and c, above, and the 'H NMR and 13C NMR spectra given low, determine a structure of this unknown molecule that is consistent with all data. Draw the structure of molecule A below 3H,3H, 2H, 1H, 1H dqd 200 180 160140 120 100 2

Explanation / Answer

2. spectral analysis

a) MS spectrum

M+ at m/z 114

CH2 = 14

O = 16

dividing = (114-16)/14 = 7

molecular formula = C7H14O

b) IHD = 1

c) IR spectrum

1662 cm-1 for C=O stretch

1649 cm-1 = for C=C stretch

d) 1H NMR shows

1.3 ppm (t, 3H) for CH3 next to CH2

4.2 ppm (q, 2H) for CH2 between CH3 and oxygen

1.7 ppm (d, 3H) for CH3 next to alkenic carbon

5.8 ppm and 6.8 ppm for alkenic protons -CH=CH-

13C NMR shows,

164 ppm for C=O carbon

Possible structure of compound,

CH3-CH=CH-COO-CH2CH3

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