MOLECULAR-STRUCTURE AND CHARGE-DISTRIBUTION OF THE 4F AND 5F ELEMENTS .3. DIPOLE-MOMENTS AND CHARGE-DISTRIBUTION OF 1/1-ADDUCTS OF TRIS(CYCLOPENTADIENYL)LANTHANOIDS(III) AND TRIS(CYCLOPENTADIENYL) ACTINOIDS(III) WITH TETRAHYDROFURAN - X-RAY STRUCTURAL-ANALYSIS OF (C5H5)3DY.THF

The dielectricity constant and the dipole moment of the 1:1 adducts of the tris(cyclopentadienyl)compounds of the trivalent lanthanoids La to Lu (with exception of the Pm compound) and of the lighter actinoids Th, U, Np, and Pu with tetrahydrofuran, (C5H5)3M(III).THF, were measured and the charge distribution within the molecule was investigated. From the partial electric moment for the metal-oxygen bond, the distribution of the 4f- and 5f-electrons to the total electric dipole moment of the molecule was calculated. The crystal and molecular structure of the (C5H5)3Dy.THF was elucidated by single crystal X-ray investigation. The tetrad effect in the compound class (C5H5)3M(III).THF is discussed.