Spectroscopy of Alcohols, Phenols, and Ethers

Ethers are difficult to identify by IR spectroscopy. Although they show an absorption due to C-0 single-bond stretching in the range 1050 to 1150 cm , many other kinds of absorptions occur in the same range. 

Carbon atoms bonded to electron-withdrawing oxygen atoms are deshielded and absorb at a lower field in the NMR spectrum than do typical alkane carbons. Most alcohol and ether carbon absorptions fall in the range 50 to 80 d. 

Phenols, like all aromatic compounds, show H NMR absorptions near 7 to 8 S, the expected position for aromatic-ring protons (Section 11.9). In addition, phenol O-H protons absorb at 3 to 8 S. In neither case are these absorptions uniquely diagnostic for phenols, since other kinds of protons absorb in the same range. 

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