论文信息 - 13C NMR and ESR spectroscopic investigations on tert‐butyl‐substituted cyclopentadienones

13C NMR and ESR spectroscopic investigations on tert‐butyl‐substituted cyclopentadienones

13C NMR spectra of 11 di-, tri- and tetra-tert-butyl-substituted cyclopentadienones are discussed with respect to charge distribution and substituent effects. The chemical shifts of the unsubstituted cyclopentadienone, calculated from substituent increments, are in good agreement with published CNDO calculations and can be rationalized by the inductive effect of the carbonyl group. In addition, the ESR signals shown by some of the cyclopentadienones are described, and possible reasons for their appearance are discussed.

H. Kalinowski | G. Maier | L. H. Franz

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