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

The ligand-field density functional theory (LFDFT) approach is employed for calculations of the Co nuclear magnetic resonance (NMR) shielding tensor of all four diastereoisomers (kkk, kkd, kdd, and ddd) of tris(1,2ethanediamine) cobalt(III) complex ion, [Co(en)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 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.