Computational analysis of tris(1,2-ethanediamine) cobalt(III) complex ion: calculation of the Co-59 shielding tensor using LF-DFT

The ligand-field density functional theory (LF-DFT) approach is employed for calculations of the Co-59 nuclear magnetic resonance (NMR) shielding tensor of all four diastereoisomers (lambda lambda lambda, lambda lambda I ', lambda I ' I ', and delta delta delta) of tris(1,2-ethanediamine) cobalt(III) complex ion, [Co(en)(3)](3+). The obtained values split into two groups according to the point group of the diastereoisomers. The influence of the individual ring conformation on the Co-59 NMR shielding tensor is small. Comparisons with results obtained with conventional DFT and experimental values are given. The good agreement between calculated and experimental values demonstrates the validity of LF-DFT for calculating the shielding tensor for transition-metal complexes