Study of rare-earth pi-complexes by means of Voronoi-Dirichlet polyhedra

An investigation of 135 pi -complexes of rare-earth atoms (Ln) was carried out with Voronoi-Dirichlet polyhedra. A novel method for the evaluation of the sizes of polyatomic ligands and steric effects in the structure of orga nometallic compounds was developed. The dependence of the domain size for L n atoms on their nature, coordinating number and oxidation state was studie d. The reasons for the occurrence of agostic Ln-H contacts were considered with a geometrical- topological analysis.