Structural Parameters and Electron Transfer in Ytterbium, Lutetium, and Cerium Compounds with Hydrocarbon Monocycles

The DFT (U)PBE0 method was used to calculate the structural parameters of the C 5 H 5 Yb·, C 5 H 5 Lu, C 8 H 8 Lu·, C 8 H 8 Yb, (C 5 H 5 ) 2 Yb, (C 5 H 5 ) 3 Yb, C 5 H 5 YbC 8 H 8 , C 5 H 5 Ce·C 8 H 8 , C 5 H 5 LuC 8 H 8 , (C 8 H 8 ) 2 Lu, (C 8 H 8 )Ce*, (C 8 H 8 ) 2 Ce, (C 8 H 8 LuC 8 H 8 ) 2 Yb, and (C 8 H 8 Ce·C 8 H 8 ) 2 Yb molecules. In the (C 8 H 8 ) 2 Ce molecule, the oxidation state of the lanthanide is higher than in the quadruple-decker (C 8 H 8 LnC 8 H 8 ) 2 Yb complexes, in the C 5 H 5 LnC 8 H 8 molecules, and in the free radicals (C 8 H 8 ) 2 Ce* and (C 8 H 8 ) 2 Lu. Oxidation of (C 5 H 5 ) 2 Yb with cyclooctatetraene and the binding of the (C 8 H 8 ) 2 Ln molecules by ytterbium(II) are exothermic reactions. The atomic charges and the dipole and quadrupole moments are indicative of incomplete transfer of the lanthanide valence electrons to the ligands, i.e., of a significant covalent component of the η 5 and η 8 bonds. Lutetium interacts with cyclooctatetraene as a lanthanide, without showing the properties of transition metals.