1,721,035 research outputs found
Dichloro-derivatives of NN'-ethylenebis(salicylideneiminato)uranium(IV) and a redistribution reaction for a uranium(IV) chelate
No full textA ligand redistribution reaction in tetrahydrofuran between Usalen2 and UCI4 led to the formation of UsalenCI2,2THF, which was also prepared by an independent method
Mixed complexes of N,N'-ethylenebis(salicylideneiminato)uranium(IV)
No full textSome mixed N,N′-ethylenebis(salicylideneiminato), salen, complexes of uranium(IV) of formula U(salen)X2(X = Cl, acetylacetonato, dipivaloylmethanato, N-methylsalicylideneiminato, dibenzoylmethanato) are reported. It is shown that U(salen)2 and UCl4 undergo a ligand redistribution reaction in tetrahydrofuran (THF) leading to U(salen)Cl2,2THF. Chemical and mass spectrometric data are presented supporting the monomeric structure of the complexes of formula U(salen)(chelate)2. Evidence is presented suggesting the transitory formation of the adduct U(salen)2,UCl4 in the course of the redistribution reaction leading to U(salen)Cl2
Coordination of cyclo-Ocatsulfur and cyclo-Heptaselenium to Dinuclear Rhenium(I) Systems
No full textDialkylcarbamato complexes of transition elements. 1. A new method for the synthesis of N,N-dialkylcarbamato and N,N-dialkyldithiocarbamato complexes of uranium(IV)
No full textCrystal and Molecular Structure of an Unsubstituted Bis(phenoxo)-derivative of Copper(II), the [{Cu(OPh)2(en)}2] •2PhOH Dimer, with a 'Normal' Magnetic Moment at Room Temperature
No full textThe title compound has been shown by X-ray diffraction methods to be a centrosymmetric phenoxo-bridged dimer with terminal phenoxo- and ethylenediamine groups and hydrogen-bonded phenol molecules. The crystals are monoclinic, space group P21/n, and the unit cell has dimensions a = 19.000(13), b = 10.930(9), c = 8.968(5) Å, β = 89.90(2)°, U = 1 862.4 Å3, and Z = 4. The structure was refined by three-dimensional Patterson and Fourier techniques up to a conventional R value of 0.0437. The copper atoms are five-co-ordinate and the co-ordination geometry is that of a distorted square pyramid. The Cu ⋯ Cu distance is 3.215 Å. The compound has a nearly normal magnetic moment at room temperature and the results of the present investigation are discussed in connection with the known magnetic and structural data for dimeric oxygen-bridged copper(II) complexes
Bis-N,N'-ethylenebis(salicylideneiminato) complexes of titanium(IV), thorium(IV) and uranium(IV), their redistribution reactions and structures of some of the mixed compounds.
No full textReactivity of molecules containing element–element bonds. I.Non transitional elements.
No full textA new method for preparing Bi2Ph4 consists of reducing BiPh21 with bis(cyclopentadienyl)cobalt(II) in tetrahydrofuran as solvent,
with yields as high as 80%. The mixed products Ph2BiEPh (E = S, Se, Te) were obtained by reacting Bi2Ph4 with &Ph2 in toluene
as solvent at room temperature. The crystal and molecular structure of BiSePh, has been solved. Crystal data: CI8Hl5BiSe,
M, = 519.3, orthorhombic, space group P212121a, = 15.936 (3) A, 6 = 11.550 (3) A, c = 8.855 (2) A, Z = 4, d(calcd) = 2.116
g cm-,. The structure consists of tricoordinated and bicoordinated bismuth and selenium, respectively, paired by a Bi-Se bond
2.704 (3) A long. The tellurium and selenium mixed species undergo diazomethane insertion with formation of the Ph2BiCH2-EPh
species. Tetraphenyldibismuthine is oxidized by elemental selenium, giving (BiPh2)2Se
Dialkylcarbamato complexes of transition elements. 2. Crystal and molecular structure of di-.mu.3-oxo-dodeca(diethylcarbamato)tetrauranium(IV)
No full textTetraphenyl derivatives of phosphorus, arsenic and antimony exchange reaction and reduction. Crystal and molecular structure of [(C4H8O2)NaAsPh2]n.
No full textThe tetraphenyl derivatives of phosphorus(I1) and arsenic(I1) P2Ph4 and As2Ph4 were found to undergo a relatively fast
exchange reaction to the mixed product Ph2PAsPh2, and the corresponding equilibria were studied in benzene, diethyl ether,
and chloroform. By measurements of equilibrium constants at different temperatures in benzene as solvent, the reaction
was found to be slightly endothermic (W = 1.3 * 0.3 kcal/mol of mixed product formed) with a positive entropy contribution
(AS' = +3.5 * 1.0 eu). The corresponding phosphorus and antimony compounds P2Ph4 and Sb2Ph4 undergo exchange
to an even lower extent, presumably due to an even more endothermic character of the reaction. Crystal data: CI6Hl8AsNaO2,
M,= 340.23, orthorhombic, a = 10.280 (1) A, b = 15.053 (2) A, c = 10.735 (1) A, Z = 4, d(ca1cd) = 1.360 g.~m-~T.h e
structure consists of an alternating sequence of dioxane-coordinated sodium atoms and Ph2As groups, giving rise to infinite
-Na-As-Na-As- chains parallel to [100]. The chains are almost linear (173.6 (1)') at arsenic and bent (121.5 (1)')
at sodium. The geometry around arsenic approximates closely that of a trigonal bipyramid. An electron deficient 2e-3c
bond involving arsenic and sodium is suggested, which appears to account also for solvation by more polar solvents such
as tetrahydrofuran
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