THE NMR-SPECTRA OF CF3I, CF3IF2, AND CF3I F4

The F-19-NMR and C-13-NMR spectra of CF3I, CF3IF2 and CF3IF4 were reco rded in acetonitrile solution. The chemical shifts of the CF3-groups a re strongly dependent on the oxidation state of the iodine atom. With increasing oxidation state the resonances of the CF3-groups in the F-1 9-NMR spectra are characteristically shifted to high field, whereas in the C-13-NMR spectra a characteristic shift to low field is measured. The absolute value of the coupling constants (1)J(F-19-C-13) increase s with increasing oxidation state from 344 Hz (CF3I) via 354 Hz (CF3IF 2) to 359 Hz (CF3IF4).