Browse
Submit Data
Databases
API
Help

Dataset Information

18 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Electrochemical studies of tris(cyclopentadienyl)thorium and uranium complexes in the +2, +3, and +4 oxidation states.

ABSTRACT: Electrochemical measurements on tris(cyclopentadienyl)thorium and uranium compounds in the +2, +3, and +4 oxidation states are reported with C₅H₃(SiMe₃)₂, C₅H₄SiMe₃, and C₅Me₄H ligands. The reduction potentials for both U and Th complexes trend with the electron donating abilities of the cyclopentadienyl ligand. Thorium complexes have more negative An(iii)/An(ii) reduction potentials than the uranium analogs. Electrochemical measurements of isolated Th(ii) complexes indicated that the Th(iii)/Th(ii) couple was surprisingly similar to the Th(iv)/Th(iii) couple in Cp''-ligated complexes. This suggested that Th(ii) complexes could be prepared from Th(iv) precursors and this was demonstrated synthetically by isolation of directly from UV-visible spectroelectrochemical measurements and reactions of with elemental barium indicated that the thorium system undergoes sequential one electron transformations.

SUBMITTER: Wedal JC

PROVIDER: S-EPMC8221189 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Uranium and thorium complexes of the phosphaethynolate ion.

Project description:New tris-amidinate actinide (Th, U) complexes containing a rare O-bound terminal phosphaethynolate (OCP - ) ligand were synthesized and fully characterized. The cyanate (OCN - ) and thiocyanate (SCN - ) analogs were prepared for comparison and feature a preferential N-coordination to the actinide metals. The Th(amid)3(OCP) complex reacts with Ni(COD)2 to yield the heterobimetallic adduct (amid) 3 Th(?-? 1 (O):? 2 (C,P)-OCP)Ni(COD) featuring an unprecedented reduced (OCP - ) bent fragment bridging the two metals.

| S-EPMC6054101 | biostudies-literature

Comparison of group 4 and thorium M(IV) substituted cyclopentadienyl silanide complexes.

Project description:We report the synthesis and characterisation of a series of M(IV) substituted cyclopentadienyl hypersilanide complexes of the general formula [M(CpR)2{Si(SiMe3)3}(X)] (M = Hf, Th; CpR = Cp', {C5H4(SiMe3)} or Cp'', {C5H3(SiMe3)2-1,3}; X = Cl, C3H5). The separate salt metathesis reactions of [M(CpR)2(Cl)2] (M = Zr or Hf, CpR = Cp'; M = Hf or Th, CpR = Cp'') with equimolar K{Si(SiMe3)3} gave the respective mono-silanide complexes [M(Cp')2{Si(SiMe3)3}(Cl)] (M = Zr, 1; Hf, 2), [Hf(Cp'')(Cp'){Si(SiMe3)3}(Cl)] (3) and [Th(Cp'')2{Si(SiMe3)3}(Cl)] (4), with only a trace amount of 3 presumably formed via silatropic and sigmatropic shifts; the synthesis of 1 from [Zr(Cp')2(Cl)2] and Li{Si(SiMe3)3} has been reported previously. The salt elimination reaction of 2 with one equivalent of allylmagnesium chloride gave [Hf(Cp')2{Si(SiMe3)3}(η3-C3H5)] (5), whilst the corresponding reaction of 2 with equimolar benzyl potassium yielded [Hf(Cp')2(CH2Ph)2] (6) together with a mixture of other products, with elimination of both KCl and K{Si(SiMe3)3}. Attempts to prepare isolated [M(CpR)2{Si(SiMe3)3}]+ cations from 4 or 5 by standard abstraction methodologies were unsuccessful. The reduction of 4 with KC8 gave the known Th(III) complex, [Th(Cp'')3]. Complexes 2-6 were characterised by single crystal XRD, whilst 2, 4 and 5 were additionally characterised by 1H, 13C{1H} and 29Si{1H} NMR spectroscopy, ATR-IR spectroscopy and elemental analysis. In order to probe differences in M(IV)-Si bonds for d- and f-block metals we studied the electronic structures of 1-5 by density functional theory calculations, showing M-Si bonds of similar covalency for Zr(IV) and Hf(IV), and less covalent M-Si bonds for Th(IV).

| S-EPMC10242453 | biostudies-literature

Synthesis and Reactivity of Cyclopentadienyl Ruthenium(II) Complexes with Tris(alkylthio)benzenes: Transformation between Dinuclear and Sandwich-Type Complexes.

Project description:To explore the structural transformation of cyclopentadienyl ruthenium (CpRu) complexes in response to external stimuli, the reaction of [RuCp(MeCN)3][X] (X = PF6, (FSO2)2N [= FSA]) and tris(alkylthio)benzenes (1,3,5-C6H3(SR)3; L 1 : R = Pr, L 2 : R = Me) was investigated, and the crystal structures and thermal properties of the products were examined. The reaction produced the sandwich complexes [RuCpL n ][X] or dinuclear complexes [Ru2Cp2(μ-L n )2(CH3CN) m ][X]2 (X = PF6, FSA) depending on the reaction conditions. The sandwich complex [RuCpL 1 ][FSA] was an ionic liquid. The solids of dinuclear complexes transformed into the thermodynamically stable sandwich complexes upon heating accompanied by acetonitrile loss. This change resulted in a transformation from crystal to ionic liquid for complexes with the FSA anion. UV irradiation of the sandwich complex [RuCpL 1 ][PF6] in methanol produced the dinuclear complex [Ru2Cp2(μ-L 1 )2 L 1 2][PF6]2. The complex transformed into the sandwich complex upon heating.

| S-EPMC7003506 | biostudies-literature

Nickel(II) uranium(IV) tris-ulfide.

Project description:Crystals of NiUS3 were obtained from the reaction of the elements Ni, U, S, and of GeI2 in a CsCl flux at 1173?K. Nickel(II) uranium(IV) tris-ulfide, NiUS3, has ortho-rhom-bic (Pnma) symmetry and crystallizes in the GdFeO3 structure type. The compound has a perovskite ABQ 3-like structure, with U occupying the inter-stitial sites of a NiS6 framework. The U atoms are coordinated by eight S atoms in a distorted bicapped trigonal-prismatic arrangement. The Ni atoms are coordinated by six S atoms in a slightly distorted octa-hedral arrangement. The asymmetric unit comprises one U site (site symmetry .m.), one Ni site (-1), and two S sites (1 and .m.).

| S-EPMC3914034 | biostudies-literature

Atomic-scale Studies of Uranium Oxidation and Corrosion by Water Vapour.

Project description:Understanding the corrosion of uranium is important for its safe, long-term storage. Uranium metal corrodes rapidly in air, but the exact mechanism remains subject to debate. Atom Probe Tomography was used to investigate the surface microstructure of metallic depleted uranium specimens following polishing and exposure to moist air. A complex, corrugated metal-oxide interface was observed, with approximately 60 at.% oxygen content within the oxide. Interestingly, a very thin (~5?nm) interfacial layer of uranium hydride was observed at the oxide-metal interface. Exposure to deuterated water vapour produced an equivalent deuteride signal at the metal-oxide interface, confirming the hydride as originating via the water vapour oxidation mechanism. Hydroxide ions were detected uniformly throughout the oxide, yet showed reduced prominence at the metal interface. These results support a proposed mechanism for the oxidation of uranium in water vapour environments where the transport of hydroxyl species and the formation of hydride are key to understanding the observed behaviour.

| S-EPMC4941397 | biostudies-literature

Tris(tetra-butyl-ammonium) tris-(nitrato-?O,O')tetra-kis-(thio-cyanato-?N)thorium(IV).

Project description:The title compound, (C(16)H(36)N)(3)[Th(NCS)(4)(NO(3))(3)], was obtained from the reaction of Th(NO(3))(4)·5H(2)O with (Bu(4)N)(NCS). The Th(IV) atom is in a ten-coordinate environment of irregular geometry, being bound to the N atoms of the four thio-cyanate ions and to three bidentate nitrate ions. The average Th-N and Th-O bond lengths are 2.481?(10) and 2.57?(3)?Å, respectively.

| S-EPMC3100005 | biostudies-literature

Thallium(I) copper(I) thorium(IV) tris-elenide, TlCuThSe(3).

Project description:Thallium(I) copper(I) thorium(IV) tris-elenide, TlCuThSe?, crystallizes with four formula units in the space group Cmcm in the KCuZrS? structure type. There is one crystallographic-ally independent Th, Tl, and Cu atom at a site of symmetry 2/m.., m2m, and m2m, respectively. There are two crystallographically independent Se atoms at sites of symmetry m.. and m2m. The structure consists of sheets of edge-sharing ThSe? octa-hedra and CuSe? tetra-hedra stacked parallel to the (010) face, separated by layers filled with chains of Tl running parallel to [100]. Each Tl is coordinated by a trigonal prism of Se atoms.

| S-EPMC3393138 | biostudies-literature

Studies of the Antiproliferative Activity of Ruthenium (II) Cyclopentadienyl-Derived Complexes with Nitrogen Coordinated Ligands.

Project description:Four cationic ruthenium(II) complexes with the formula [Ru(eta(5)-C(5)H(5))(PPh(3))(2)](+), with L = 5-phenyl-1H-tetrazole (TzH) 1, imidazole (ImH) 2, benzo[1,2-b;4,3-b'] dithio-phen-2-carbonitrile (Bzt) 3, and [5-(2-thiophen-2-yl)-vinyl]-thiophene-2-carbonitrile] (Tvt) 4 were prepared and characterized in view to evaluate their potentialities as antitumor agents. Studies by Circular Dichroism indicated changes in the secondary structure of ct-DNA. Changes in the tertiary structure of pBR322 plasmid DNA were also observed in gel electrophoresis experiment and the images obtained by atomic force microscopy (AFM) suggest strong interaction with pBR322 plasmid DNA; the observed decreasing of the viscosity with time indicates that the complexes do not intercalate between DNA base pairs. Compounds 1, 2, and 3 showed much higher cytotoxicity than the cisplatin against human leukaemia cancer cells (HL-60 cells).

| S-EPMC2905958 | biostudies-literature

Contrasting behaviour under pressure reveals the reasons for pyramidalization in tris(amido)uranium(III) and tris(arylthiolate) uranium(III) molecules.

Project description:A range of reasons has been suggested for why many low-coordinate complexes across the periodic table exhibit a geometry that is bent, rather a higher symmetry that would best separate the ligands. The dominating reason or reasons are still debated. Here we show that two pyramidal UX3 molecules, in which X is a bulky anionic ligand, show opposite behaviour upon pressurisation in the solid state. UN″3 (UN3, N″ = N(SiMe3)2) increases in pyramidalization between ambient pressure and 4.08 GPa, while U(SAr)3 (US3, SAr = S-C6H2-tBu3-2,4,6) undergoes pressure-induced planarization. This capacity for planarization enables the use of X-ray structural and computational analyses to explore the four hypotheses normally put forward for this pyramidalization. The pyramidality of UN3, which increases with pressure, is favoured by increased dipole and reduction in molecular volume, the two factors outweighing the slight increase in metal-ligand agostic interactions that would be formed if it was planar. The ambient pressure pyramidal geometry of US3 is favoured by the induced dipole moment and agostic bond formation but these are weaker drivers than in UN3; the pressure-induced planarization of US3 is promoted by the lower molecular volume of US3 when it is planar compared to when it is pyramidal.

| S-EPMC9262880 | biostudies-literature

Distribution of uranium and thorium chains radionuclides in different fractions of phosphogypsum grains.

Project description:This work presents results obtained using gamma spectrometry measurements of phosphogypsum samples on a non-fractionated (native) and fractionated phosphogypsum byproduct. The phosphogypsum was divided into particles size fractions within the range of <?0.063, 0.063-0.090, 0.090-0.125, 0.125-0.250, and over 0.250 mm and analyzed after reaching radioactive equilibrium using high-resolution gamma spectrometry technique. It was found that there is no significant differentiation between 226Ra distribution among particular grain size fractions of this material; however, tendency for preferential retention of radionuclides in particular grain size fractions is observed. The detailed analysis of results revealed that radium is preferentially retained in smaller grain size fractions, whereas lead and thorium in coarse fractions. The results indicate that overall 226Ra activity concentrations between particular fractions of phosphogypsum vary globally between -?34 and +?47% regarding non-fractionated material, and for 210Pb activity concentration, fluctuations are found between -?26 up and +?38%. Presumably, the mechanism of radium incorporation into gypsum phase is based on a sequence of radium bearing sulfate phases formation followed by a surface adsorption of these phases on the calcium sulfate crystals, whereas for lead and thorium ions, rather incorporation into crystal lattice should be expected as more likelihood process.

| S-EPMC7190684 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data