Xl. Xie et al., FPT-CNDO 2 STUDIES OF CO-59 CHEMICAL SHIELDING CONSTANTS IN HEXACOORDINATED DIAMAGNETIC CO(III) COMPLEXES/, Journal of molecular structure. Theochem, 331(1-2), 1995, pp. 181-185
The Co-59 nuclear shielding constants of five hexacoordinated diamagne
tic cobalt(III) complexes have been calculated using a semiempirical m
olecular orbital method within the framework of the finite perturbatio
n theory, the FPT-CNDO/2 method. Experimental and calculated chemical
shifts referenced to the cobalticyanide anion gave good agreement. The
difference between the calculated and the experimental chemical shift
s is attributed to the underestimation of the radial factor. The origi
n of the shielding on the cobalt nucleus is discussed in terms of the
3d orbital population. The shielding anisotropy in the compounds with
low symmetry is also surveyed.