Oxygen-17 nuclear magnetic resonance of inorganic compounds

The 17O chemical shifts of a number of com pounds have been measured at 6.000 Mc/s in the liquid or solution state. The resonances observed for the ‘closed-shell’ oxy-anions of the transition metals indicate a high degree of paramagnetic shielding of the oxygen nuclei for these anions. A linear relationship has been observed between the chemical shifts for these anions and their lowest-energy electronic transitions as obtained from u.v. and visible spectra. Calculations in term s of a molecular orbital model for these anions have successfully accounted for this relationship and at the same time have produced a mechanism for the observed paramagnetic shielding. It has been shown that a similar linear relationship exists in the cases of organic carbonyl compounds for which nuclear resonance and optical spectral data are available.