Abstract The 13 C NMR spectra for selected 2-iodosobenzoic acids, their sodium salts and the sodium salts of the corresponding iodoxybenzoic acids were measured and carbon assignments made using 2D and NOE experiments and relaxation times. Iodoso and iodoxy groups deshielded the ipso-carbon in these compounds by approximately 25 and 55 ppm, respectively, relative to the corresponding iodo compounds. The 13 C NMR spectra of the ...