CHEMICAL-SHIFTS IN CO-59 NUCLEAR MAGNETIC-RESONANCE SPECTRA OF LOW-SYMMETRY LIGAND-FIELD CO(III) COMPLEX-COMPOUNDS

It has been shown that for the trischelate CoN6-xOx (x = 0-6) type of complexes, deviation from the Griffith-Orgel relation, i.e., from the linear relationship between 59Co chemical shifts and the wavelength of the first absorption maxima in the visible region of the spectrum in complexes of low-symmetry ligand field, is due to the anisotropy of chemical shielding of Co(III). By resolving the first absorption band into constituent components and determining the shielding as a mean value of screening along individual axes, it has been established that the 59Co chemical shift in the Co(III) complex compounds investigated is in a linear relationship with a weighted average wavelength of the first absorption band. © 1979.