Figure 9.47
The INADEQUATE spectrum of geraniol in CD 3 COCD 3 at 75.6^
MHz for^13 C.Qualitative Analysis – The Identification of Structural Features
PMR spectrometry is an extremely useful technique for the identification and structural analysis of
organic compounds in solution, especially when used in conjunction with infrared, ultraviolet, visible
and mass spectrometry. Interpretation of PMR spectra is accomplished by comparison with reference
spectra and reference to chemical shift tables. In contrast to infrared spectra, it is usually possible to
identify all the peaks in a PMR spectrum, although the complete identification of an unknown
compound is often not possible without other data. Some examples of PMR spectra are discussed
below.
Figure 9.48 shows the spectrum of 4-ethoxyacetanilide in CDCl 3. The triplet and quartet indicate the
presence of an ethyl group, and tables show that the chemical shift of the methylene quartet (δ4.0),
appearing well downfield, is due to –OPh. The aromatic ring protons are seen around δ7, the somewhat
symmetrical pattern suggesting a 1,4-substituted compound, and the upfield group at δ6.8 corresponds
to ring protons ortho to the