1284-81-7Relevant academic research and scientific papers
ZUR KENNTNIS DES DIAQUA-TRIS(η5-CYCLOPENTADIENYL)URAN(IV)KATIONS: ISOLIERUNG UND EIGENSCHAFTEN DES SALZES NO3
Fischer, R.D.,Klaehne, E.,Sienel, G.R.
, p. 99 - 112 (1982)
In contrast to the re-examined system which appears to contain weakly hydrogen-bonded H2O rather than a genuine + cation, the salt-like precipitate NO3 is shown to be the first well-defined +-derivative of adequate stability, the anion of which is not coordinated to the central metal.Ample evidence for the existense of similar, but mostly metastable precipitation products X and , respectively, (X = e.g.Cl, Br, I, ClO4, HCO2 including the replacement of H2O by NH3) is presented.Some interesting, common features of organo-uranium- and -tin-systems, R3MIVX, are elucidated.
Oxidative addition of organic halides to (ν-C5H5)3U(THF) (THF = tetrahydrofuran). A convenient new synthesis of triscyclopentadienyl uranium(IV) hydrocarbyl complexes
Villiers, Claude,Ephritikhine, Michel
, p. 339 - 342 (1990)
Cp3U(THF) (Cp = η-C5H5; THF = tetrahydrofuran) react with organic halides RX to give the equimolecular mixture of the Cp3UX and Cp3UR compounds.The features of the reaction are characteristic of an atom abstraction oxidative addition mechanism.Treatment o
Molecular structure and charge distribution in organometallics of the 4f and 5f elements. I. Dipole moment and charge distribution of the actinoid(IV) tetracyclopentadienides, An(C5H5)4
Kanellakopulos,Maier,Heuser
, p. 89 - 96 (1991)
The dipole moments of the tetracyclopentadienides, An(C5H5)4, of the lighter actinoids thorium, uranium and neptunium were measured in benzene solution. Although the compounds in the solid state have a quasi-Td molecular symmetry their dipole moments are not zero, owing to lowering of the molecular symmetry. The origin of the nonzero dipole moments is discussed.
Reactions of uranium cyclopentadienyl compounds with some alkyl and arylchlorides
Leonov, M. R.,Gramoteeva, N. I.,Il'yushenkov, V. A.,Pogodina, L. A.
, p. 228 - 230 (2008/10/08)
Uranium cyclopentadienyl compounds Cp4U, Cp3U-n-Bu, and Cp3U-i-Bu (Cp = η5-C5H5, Bu = C4H9) react with alkyl and aryl chlorides n-BuCl, t-BuCl, and BzCl (Bz = CH2C6H5) at an appreciable rate in the temperature range 25-80°C depending on the structure of the reactants. When thehalide is taken in a six- to tenfold excess, the reaction time decrease s by an order of magnitude. The major products of reactions of Cp4U withn-BuCl and t-BuCl are, respectively, Cp3U-n-Bu and Cp3UCH2C(CH3)2Cl, an d with BzCl, Cp3UBz (at a threefold excess of BzCl, CpUBz3). With a 30-fold excess of t-BuCl and BzCl, Cp4U gives, respectively, CpU[CH2C(CH3)2Cl]3 and CpUBz3. These compounds are characterized by a high extent of coordination unsaturation of the uranium atom and probably catalyze the concomitant polycondensation of the alkyl and aryl chlorides taken into the reaction. Reactions of Cp3U-n-Bu and Cp3U-i-Bu with BzCl gave Cp3UCl and the corresponding amylbenzenes.
Bi- and triheteronuclear complexes of uranium and group VI transition metals
Dormond, Alain,Moise, Claude
, p. 595 - 598 (2008/10/08)
The new heterobimetallic compounds Cp3U[OCM(CO)2Cp′] containing uranium and group VI transition metals are synthesized from Cp3UCl and Na[M(CO)3Cp′] or from Cp3UCH3 and H[M(CO)3Cp′] (M = Mo, W; Cp = C5H5; Cp′ = C5H5 or C5Me5). In a same manner, the trimetallic Cp2U[OCMo(CO) 2Cp]2 is obtained starting from Cp2U(NEt2)2 and H[Mo(CO)3Cp]. All these complexes exhibit low CO stretching frequencies characteristic of isocarbonyl linkages between uranium and Mo or W atoms.
COMPLEXES BISCYCLOPENTADIENYLES DISSYMETRIQUES ET TRISCYCLOPENTADIENYLES MIXTES DE L'URANIUM(IV). U COMME CENTRE DE PSEUDOASYMETRIE
Dormond, A.
, p. 47 - 56 (2007/10/02)
Starting from the monocyclopentadienyls U(C5Me4R)X3 (X = Cl or NEt2, R = CH3 or C2H5), the bis-cyclopentadienyl dissymetric complexes U(C5Me4R)CpX2 (Cp = substituted or unsubstituted cyclopentadienyl ligand) and the tris-cyclopentadienyl complexes U(C5Me4R)Cp2Cl are obtained.If the two Cp ligands have a chiral center, a mixture of one racemic and two meso isomers is obtained.In the meso isomers, the uranium atom is a pseudoasymmetric center.
Crystal and molecular structure of (η-C5H5)3U=CHP(CH3) 2(C6H5). A compound with a uranium-carbon multiple bond
Cramer, Roger E.,Maynard, Richard B.,Paw, Josephine C.,Gilje, John W.
, p. 1336 - 1340 (2008/10/08)
The structure of the complex (η5-C5H5)3U=CHP(CH 3)2(C6H5) has been determined by single-crystal X-ray methods. The compound crystallizes with four molecles in space group P21/c of the monoclinic system in a cell with dimensions of a = 10.835 (2) A?, b = 8.481 (2) A?, c = 25.57 (1) A?, β = 111.77 (3)°, V = 2182 A?3, and ρcalcd = 1-78 g/cm3. The structure has been refined by least-squares methods to a final R index on F of 0.071 for the 91 variables and 1985 data. The uranium is bound in a tetrahedral fashion to three cyclopentadienyl ligands and a CHP(CH3)2(C6H5) ligand. The bond to the carbon atom of the phosphoylide ligand, 2.29 (3) A?, is the shortest U-C bond yet observed, and this is interpreted as indicating mutliple bonding in the U-C bond.
COMPLEXES CYCLOPENTADIENYLES DE L'URANIUM(IV). II. COMPLEXES TRICYCLOPENTADIENYLES D'URANIUM(IV) A CHIRALITE CENTRO-METALLEE. DIASTEREOTOPIE ET DIASTEREOISOMERIE
Dormond, A.,Duval-Huet, C.,Tirouflet, J.
, p. 341 - 354 (2007/10/02)
The synthesis of η5-Cp'3UCl, η5-Cp-η5-Cp'2UCl, η5-Cp2-η5-Cp'UCl (Cp = C5H5; Cp' = substituted cyclopentadienyl) complexes and of similar complexes bridged between the two cyclopentadienyl ligands is described.Several complexes of this type have a prochiral uranium atom.The bridged complexes obtained from the bidentate dianion 2- bear a chiral carbon and a chiral uranium atom in the same structure.The two diastereoisomeric forms have not been separated but are easily identified by NMR analysis.
