Organic Chemistry Semester 1 LABORATORY MANUAL - Moravian ...

Infrared Spectroscopy Appendix C8 Part V. Techniques and Theory
IR Additional Out of Class Applications:
1. Predict approximate values of important IR ν's for the following compounds:
O
O CH 3
c.
a.
b. CH 3 NH 2
O
N
H
d. CH 3 CH 2 C N
2. What functional groups are likely to be present in each of the following compounds
Explain your logic.
(1.) C 4 H 6 O 3025, 2940, 2800, 2720, 1680 (st), 1630 cm -1
(2.) C 7 H 8 O 3300 (br & st), 3040, 2940, 1610, 1570, 1480, 1460, 1160 cm -1
(3.) C 9 H 10 O 3020, 2955, 1690 (st), 1600, 1590, 1460 cm -1
(4.) C 7 H 7 NO 2 3460, 3360, 3000 (br-st), 1670, 1640, 1180 cm -1
3. For the following pair of structures, if you had the IR spectrum of a reaction product that had
to be one of the compounds, how could you use the spectrum to distinguish between the two
possible structures Explain how.
vs.
H
O
O
4. What functional groups might be present in the molecule that produced the following set of
data Give one or two possible structures that are consistent with the molecular formula and
the spectrum. Explain your logic.
C 5 H 8 O
4000
3600
3200
2800
2400
FREQUENCY (CM -1 )
2000 1800 1600 1400
1200
1000
800
600
400
80
Transmittance (%)
60
40
20
0