Theoretical investigation on organolanthanide guanidinate complexes

Density functional theory (DFT) calculations were carried out on the compounds Cp2Ln-guan for Ln=Y, Lu, Yb, Dy and Gd, [guan=(iPrN)2CN(iPr)2]. The results were compared with the X-ray structures that were available from the literature; the calculations reproduced quite well the experimental structural features in these complexes exhibiting distorted tetrahedron geometry. The calculated evolution of the Ln-guan bond as a function of the cation showed that lanthanide-ligand distances increased with the increase of the ionic radius; but for lanthanide-guan Hirschfield charge Cp2Dy-guan made the exception where we found that the bond in this complex was the most ionic.