Ernst Dornberger

Homoscorpionates (hydridotris(1-pyrazolyl)borato complexes) of the trivalent 4fions. The crystal and molecular structure of [(HB(N2C3H3)3]3LnIII, (Ln Pr, Nd) ☆

Abstract The compounds [( η 3 -HB(N 2 C 3 H 3 ) 3 ] 3 M of scandium, yttrium, lanthanum and of the trivalent lanthanides from cerium to lutetium (with the exception of promethium) have been synthesized by the reaction of MCl 3 with K[HB(N 2 C 3 H 3 ) 3 ] in tetrahydrofuran or in water. The crystal and molecular structures of the Pr and Nd compounds were determined by single-crystal X-ray diffraction. The crystal structure corresponds to the structure of the praseodymium trichloride (LaCl 3 -type). The Pr 3+ is nine-coordinate to the N atoms of the three Tp ligands. One N atom of each of the three Tp ligands and the Pr ion are almost coplanar with a PrN distance of 278.3 pm, while all other six N atoms are at a distance of 260.9 pm in a tricapped trigonal prismatic arrangement. The MN distances in the Nd compound are 280.4 (3 x) and 259.9 (6 x) pm. IR spectroscopic studies have shown that the metal ion in the LnTp 3 compounds from La to Dy is nine-coordinate, while in the compounds of the heavier lanthanides from Ho to Lu, of Sc, and Y, the central ion is eight-coordinate.

Über eine neue präparative methode zur synthese metallorganischer verbindungen

Abstract Ammonium salts react with pure cyclopentadienyl compounds of the 4f-, 5f- and nd- elements to give substituted matallorganic compounds. A series of new metallorganic uranium (IV) compounds of the type (C5H5)3UX (X NO3, ClO4, ReO4, B(C6H5)4) and (C5H5)3UYU(C5H5)3 (Y  sulfate-, oxalatedianion) were prepared. Further the compounds U[B(C6H5)4]4 and (C5H5)2 ThCl have been for the first time synthesized. The new compounds have been characterised and investigated.

Koordinative komplexe des antibasen—basen-systems urantetrachlorid und tricyclopentadienyluran(IV)-chlorid

Abstract Novel coordination compounds of uranium tetrachloride with tricyclopentadienyluranium(IV) chloride of the compositions [(C 5 H 5 ) 3 U] 2 UCl 6 · 2DME, [(C 5 H 5 ) 3 U] 2 UCl 6 and [(C 5 H 5 ) 3 U]UCl 5 have been synthesized by the following reactions in dimethoxyethane: (a) UCl 4 + 2TlC 5 H 5 , (b) UCl 4 + U(C 5 H 5 ) 4 and (c) UCl 4 + 2(C 5 H 5 ) 3 UCl. The solvent-free compounds have been prepared in benzene in a similar manner. The physical and chemical properties of these compounds are reported.

Oxo-bridged bimetallic organouranium complexes: The crystal structure of μ-oxo-bis[tris(cyclopentadienyl)uranium(IV)]

Abstract Oxidation of (C 5 H 5 ) 3 U III ·THF with oxygen in tetrahydrofuran yields the linear bridged complex [(C 5 H 5 ) 3 U][μ-O]. Three cyclopentadienyl rings are η 5 -covalently bonded to each uranium atom to form a distorted tetrahedron with one bridging oxygen atom. The UOU angle is 180° with the oxygen atom on a centre of inversion. The UO distance, 2.0881(4) A, is among the shortest ever observed. The temperature-dependent paramagnetic susceptibility of the compound was measured in the temperature range between 4.2 and 300 K and is discussed in comparison with the magnetic susceptibilities of (C 5 H 5 ) 3 UOH, (C 5 H 5 ) 3 USH and [(C 5 H 5 ) 3 U] 2 [μ-S].

Metallorganische Verbindungen des Technetiums: VI. Darstellung und Charakterisierung von Verbindungen des Typs LTc(CO)3 (L C5Me5, C5Me4Et, C9H7); Röntgenstrukturanalysen von (η5-C5Me5)M(CO)3 (M Tc, Re), (η5-C5Me4Et)Tc(CO)3 sowie (η5-C9H7)Tc(CO)3

Abstract The compounds LTc(CO) 3 (L  C 5 Me 5 , C 5 Me 4 Et, Ind) were synthesized for the first time and their structures as well as the well-known (C 5 Me 5 )Re(CO) 3 were determined by single-crystal X-ray diffraction. The IR, 1 H NMR, 13 C NMR and the UV spectra are reported and discussed.

CRYSTALLIZATION AND X-RAY STRUCTURES OF NAYB(C5H5)3 AND YB(C5H5)2

The complex [NaYb(C 5 H 5 ) 3 ] (C 5 H 5 = cyclopentadienyl), prepared from Yb(C 5 H 5 ) 3 and sodium naphthalenide in tetrahydrofuran (thf) or from Yb(C 5 H 5 ) 2 and Na(C 5 H 5 ) in tetrahydrofuran and crystallized at ca. 400 °C (<10 - 4 mm Hg), is a three-dimensional polymer in which µ-η 5 :η 5 -C 5 H 5 groups link sodium and ytterbium (each metal having a pseudo-triangular arrangement of C 5 H 5 ligands); Yb(C 5 H 5 ) 2 , similarly crystallized, has a polymeric chain structure with one terminal and two bridging C 5 H 5 ligands per ytterbium, and there is η 1 -bonding between adjacent chains.

The Energy Gap of the Lowest Manifolds in Americium Triscyclopentadienide

The preparation and investigation of Americium triscyclopentadienide is reported. The compound crystallizes in the orthorhombic group Pbcm with the lattice parameters a = 14.08 ± 0.2, b = 17.55 ± 0.02 and c = 19.66 ± 0.02 A. The magnetic susceptibility of the compound was measured between 4.2 and 300 Κ and the paramagnetism is discussed. The deviation from the expected temperature independent molar susceptibility, for the trivalent Americium ion at low temperatures, is assumed to be attributed to the presence of Am 2 + formed by radiolysis and the reducing influence of the cyclopentadienyl ligands.