Über die Funktion des Kations und der Solvatmolekeln in kristallisierten Monocyclopentadienyl–Anionen-Komplexen des Chroms

On the function of the cation and solvent molecules in crystallized chromium monocyclopentadienyl complexes The two structure types for monocyclopentadienyl-chromium complexes, proposed by Fischer and by Otto, are equivalent ones, regarding the bonding character. The cation, existing only for structure type I, contributes to the charge neutrality, behaves, in combination with only one field ligand, as an ?electron donor”?, and allows for the characteristic ligand field symmetry C_s for these complexes. The solvate molecules exert a stabilizing effect both via attenuating the polarizing action of the cations and via their arrangement in the crystal lattice.