Oxygen-17 Nuclear Magnetic Resonance. III. Oxygen Atoms with a Coordination Number of Two

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Abstract
Fourier transform 17O NMR spectra have been measured for a number of alcohols, ethers, acetals, formates, acetates, and esters of inorganic acids in natural abundance at 10.8 MHz. The 17O chemical shifts which cover a range as large as several hundred ppm are primarily governed by the sum of electronegativity of the first atoms or groups attached to the central oxygen. The downfield shift due to β-methyl groups in alcohols and ethers is in parallel with decrease in their ionization potentials, demonstrating the importance of the paramagnetic screening term in the 17O shifts of these compounds. Diamagnetic shift due to γ-carbons and -oxygens has also been disclosed.