Organic Chemistry

524 CHAPTER 13 Mass Spectrometry and Infrared Spectroscopy

Wavelength (μm)

Wavenumber (cm−^1 )

2.52.6 2.7 2.8 2.9 3 3.5 4 4.5 5 5.5 6 7 8 9 10 11 12 13 14 15 16

4000380036003400320030002800260024002200 2000 1800 1600 1400 1200 1000 800 600

% Transmittance

Figure 13.46

The IR and mass spectra for Problem 54b.

2.52.6 2.7 2.8 2.9 3 3.5 4 4.5 5 5.5 6 7 8 9 10 11 12 13 14 15 16

4000380036003400320030002800260024002200 2000 1800 1600 1400 1200 1000 800 600

0 20 40 60 80 100 120

m/z

43

71 85

100

58

29

100

50

0

Relative abundance

Wavelength (μm)

Wavenumber (cm−^1 )

% Transmittance

Figure 13.45

The IR and mass spectra for Problem 54a.

52. Determine the molecular formula of a saturated acyclic hydrocarbon with an M peak at with a relative intensity of
    27.32%, and an peak with a relative intensity of 2.10%.


53. Calculate the approximate wavenumber at which a stretch will occur, given that the force constant for the bond is


54. The IR and mass spectra for three different compounds are shown in Figures 13.45–13.47. Identify each compound.

10 * 105 gs-^2.

C“C C“C

M+ 1

m>z= 100