Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A Structurally Characterized Organometallic Plutonium(IV) Complex.

ABSTRACT: The blood-red plutonocene complex Pu(1,3-COT'')(1,4-COT'') (4; COT''=η⁸ -bis(trimethylsilyl)cyclooctatetraenyl) has been synthesized by oxidation of the anionic sandwich complex Li[Pu(1,4-COT'')₂ ] (3) with anhydrous cobalt(II) chloride. The first crystal structure determination of an organoplutonium(IV) complex revealed an asymmetric sandwich structure for 4 where one COT'' ring is 1,3-substituted while the other retains the original 1,4-substitution pattern. The electronic structure of 4 has been elucidated by a computational study, revealing a probable cause for the unexpected silyl group migration.

SUBMITTER: Apostolidis C

PROVIDER: S-EPMC5485009 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

A Structurally Characterized Organometallic Plutonium(IV) Complex.

Apostolidis Christos C Walter Olaf O Vogt Jochen J Liebing Phil P Maron Laurent L Edelmann Frank T FT

Angewandte Chemie (International ed. in English) 20170330 18

The blood-red plutonocene complex Pu(1,3-COT'')(1,4-COT'') (4; COT''=η<sup>8</sup> -bis(trimethylsilyl)cyclooctatetraenyl) has been synthesized by oxidation of the anionic sandwich complex Li[Pu(1,4-COT'')<sub>2</sub> ] (3) with anhydrous cobalt(II) chloride. The first crystal structure determination of an organoplutonium(IV) complex revealed an asymmetric sandwich structure for 4 where one COT'' ring is 1,3-substituted while the other retains the original 1,4-substitution pattern. The electroni ...[more]

PMID: 28371148

Similar Datasets

Structurally characterized terminal manganese(iv) oxo tris(alkoxide) complex.

Project description:A Mn(iv) complex featuring a terminal oxo ligand, [MnIV(O)(ditox)3][K(15-C-5)2] (3; ditox = t Bu2MeCO-, 15-C-5 = 15-crown-5-ether) has been isolated and structurally characterized. Treatment of the colorless precursor [MnII(ditox)3][K(15-C-5)2] (2) with iodosobenzene affords 3 as a green free-flowing powder in high yields. The X-ray crystal structure of 3 reveals a pseudotetrahedral geometry about the central Mn, which features a terminal oxo (d(Mn-Oterm = 1.628(2) Å)). EPR spectroscopy, SQUID magnetometry, and Evans method magnetic susceptibility indicate that 3 consists of a high-spin S = 3/2 Mn(iv) metal center. 3 promotes C-H bond activation by a hydrogen atom abstraction. The [MnIV(O)(ditox)3]- furnishes a model for the proposed terminal oxo of the unique manganese of the oxygen evolving complex of photosystem II.

| S-EPMC5958342 | biostudies-literature

A Stable Homoleptic Organometallic Iron(IV) Complex.

Project description:A homoleptic organometallic FeIV complex that is stable in both solution and in the solid state at ambient conditions has been synthesized and isolated as [Fe(phtmeimb)2 ](PF6 )2 (phtmeimb=[phenyl(tris(3-methylimidazolin-2-ylidene))borate]- ). This FeIV N-heterocyclic carbene (NHC) complex was characterized by 1 H NMR, HR-MS, elemental analysis, scXRD analysis, electrochemistry, Mößbauer spectroscopy, and magnetic susceptibility. The two latter techniques unequivocally demonstrate that [Fe(phtmeimb)2 ](PF6 )2 is a triplet FeIV low-spin S=1 complex in the ground state, in agreement with quantum chemical calculations. The electronic absorption spectrum of [Fe(phtmeimb)2 ](PF6 )2 in acetonitrile shows an intense absorption band in the red and near IR, due to LMCT (ligand-to-metal charge transfer) excitation. For the first time the excited state dynamics of a FeIV complex was studied and revealed a ≈0.8 ps lifetime of the 3 LMCT excited state of [Fe(phtmeimb)2 ](PF6 )2 in acetonitrile.

| S-EPMC7590184 | biostudies-literature

Structurally Characterized BODIPY-Appended Oxidovanadium(IV) ?-Diketonates for Mitochondria-Targeted Photocytotoxicity.

Project description:Mixed-ligand oxidovanadium(IV) ?-diketonates having NNN-donor dipicolylamine-conjugated to boron-dipyrromethene (BODIPY in L1) and diiodo-BODIPY (in L2) moieties, namely, [VO(L1)(acac)]Cl (1), [VO(L2)(acac)]Cl (2), and [VO(L1)(dbm)]Cl (3), where acac and dbm are monoanionic O,O-donor acetylacetone and 1,3-diphenyl-1,3-propanedione, were prepared, characterized, and tested for their photoinduced anticancer activity in visible light. Complexes 1 and 2 were structurally characterized as their PF6 - salts (1a and 2a) by X-ray crystallography. They showed VIVN3O3 six-coordinate geometry with dipicolylamine base as the facial ligand. The non-iodinated BODIPY complexes displayed absorption maxima at ?501 nm, while it is ?535 nm for the di-iodinated 2 in 10% DMSO-PBS buffer medium (pH = 7.2). Complexes 1 and 3 being green emissive (?em, ?512 nm; ?ex, 470 nm; ?F, ?0.10) in 10% aqueous DMSO were used for cellular imaging studies. Complex 3 localized primarily in the mitochondria of the cervical HeLa cells with a co-localization coefficient value of 0.7. The non-emissive diiodo-BODIPY complex 2 showed generation of singlet oxygen (?? ? 0.47) on light activation. Annexin-V assay showed singlet oxygen-mediated cellular apoptosis, making this complex a targeted PDT agent.

| S-EPMC7057700 | biostudies-literature

A Structurally Characterized Cobalt(I) σ-Alkane Complex.

Project description:A cobalt σ-alkane complex, [Co(Cy2 P(CH2 )4 PCy2 )(norbornane)][BArF 4 ], was synthesized by a single-crystal to single-crystal solid/gas hydrogenation from a norbornadiene precursor, and its structure was determined by X-ray crystallography. Magnetic data show this complex to be a triplet. Periodic DFT and electronic structure analyses revealed weak C-H→Co σ-interactions, augmented by dispersive stabilization between the alkane ligand and the anion microenvironment. The calculations are most consistent with a η1 :η1 -alkane binding mode.

| S-EPMC7187152 | biostudies-literature

Plutonium(IV) Sorption during Ferrihydrite Nanoparticle Formation.

Project description:Understanding interactions between iron (oxyhydr)oxide nanoparticles and plutonium is essential to underpin technology to treat radioactive effluents, in cleanup of land contaminated with radionuclides, and to ensure the safe disposal of radioactive wastes. These interactions include a range of adsorption, precipitation, and incorporation processes. Here, we explore the mechanisms of plutonium sequestration during ferrihydrite precipitation from an acidic solution. The initial 1 M HNO3 solution with Fe(III)(aq) and 242Pu(IV)(aq) underwent controlled hydrolysis via the addition of NaOH to pH 9. The majority of Fe(III)(aq) and Pu(IV)(aq) was removed from solution between pH 2 and 3 during ferrihydrite formation. Analysis of Pu-ferrihydrite by extended X-ray absorption fine structure (EXAFS) spectroscopy showed that Pu(IV) formed an inner-sphere tetradentate complex on the ferrihydrite surface, with minor amounts of PuO2 present. Best fits to the EXAFS data collected from Pu-ferrihydrite samples aged for 2 and 6 months showed no statistically significant change in the Pu(IV)-Fe oxyhydroxide surface complex despite the ferrihydrite undergoing extensive recrystallization to hematite. This suggests the Pu remains strongly sorbed to the iron (oxyhydr)oxide surface and could be retained over extended time periods.

| S-EPMC7011701 | biostudies-literature

A structurally-characterized peroxomanganese(iv) porphyrin from reversible O2 binding within a metal-organic framework.

Project description:The role of peroxometal species as reactive intermediates in myriad biological processes has motivated the synthesis and study of analogous molecular model complexes. Peroxomanganese(iv) porphyrin complexes are of particular interest, owing to their potential ability to form from reversible O2 binding, yet have been exceedingly difficult to isolate and characterize in molecular form. Alternatively, immobilization of metalloporphyrin sites within a metal-organic framework (MOF) can enable the study of interactions between low-coordinate metal centers and gaseous substrates, without interference from bimolecular reactions and axial ligation by solvent molecules. Here, we employ this approach to isolate the first rigorously four-coordinate manganese(ii) porphyrin complex and examine its reactivity with O2 using infrared spectroscopy, single-crystal X-ray diffraction, EPR spectroscopy, and O2 adsorption analysis. X-ray diffraction experiments reveal for the first time a peroxomanganese(iv) porphyrin species, which exhibits a side-on, η2 binding mode. Infrared and EPR spectroscopic data confirm the formulation of a peroxomanganese(iv) electronic structure, and show that O2 binding is reversible at ambient temperature, in contrast to what has been observed in molecular form. Finally, O2 gas adsorption measurements are employed to quantify the enthalpy of O2 binding as hads = -49.6(8) kJ mol-1. This enthalpy is considerably higher than in the corresponding Fe- and Co-based MOFs, and is found to increase with increasing reductive capacity of the MII/III redox couple.

| S-EPMC5890324 | biostudies-literature

Plutonium (IV) Quantification in Technologically Relevant Media Using Potentiometric Sensor Array.

Project description:The quantification of plutonium in technological streams during spent nuclear fuel (SNF) reprocessing is an important practical task that has to be solved to ensure the safety of the process. Currently applied methods are tedious, time-consuming and can hardly be implemented in on-line mode. A fast and simple quantitative plutonium (IV) analysis using a potentiometric sensor array based on extracting agents is suggested in this study. The response of the set of specially designed PVC-plasticized membrane sensors can be related to plutonium content in solutions simulating real SNF-reprocessing media through multivariate regression modeling, providing 30% higher precision of plutonium quantification than optical spectroscopy.

| S-EPMC7147468 | biostudies-literature

Addition of dioxygen to an N4S(thiolate) iron(II) cysteine dioxygenase model gives a structurally characterized sulfinato-iron(II) complex.

Project description:The non-heme iron enzyme cysteine dioxygenase (CDO) catalyzes the S-oxygenation of cysteine by O(2) to give cysteine sulfinic acid. The synthesis of a new structural and functional model of the cysteine-bound CDO active site, [Fe(II)(N3PyS)(CH(3)CN)]BF(4) (1) is reported. This complex was prepared with a new facially chelating 4N/1S(thiolate) pentadentate ligand. The reaction of 1 with O(2) resulted in oxygenation of the thiolate donor to afford the doubly oxygenated sulfinate product [Fe(II)(N3PySO(2))(NCS)] (2), which was crystallographically characterized. The thiolate donor provided by the new N3PyS ligand has a dramatic influence on the redox potential and O(2) reactivity of this Fe(II) model complex.

| S-EPMC3403739 | biostudies-literature

Location-Dependent Lanthanide Selectivity Engineered into Structurally Characterized Designed Coiled Coils.

Project description:Herein we report unprecedented location-dependent, size-selective binding to designed lanthanide (Ln3+ ) sites within miniature protein coiled coil scaffolds. Not only do these engineered sites display unusual Ln3+ selectivity for moderately large Ln3+ ions (Nd to Tb), for the first time we demonstrate that selectivity can be location-dependent and can be programmed into the sequence. A 1 nm linear translation of the binding site towards the N-terminus can convert a selective site into a highly promiscuous one. An X-ray crystal structure, the first of a lanthanide binding site within a coiled coil to be reported, coupled with CD studies, reveal the existence of an optimal radius that likely stems from the structural constraints of the coiled coil scaffold. To the best of our knowledge this is the first report of location-dependent metal selectivity within a coiled coil scaffold, as well as the first report of location-dependent Ln3+ selectivity within a protein.

| S-EPMC8597134 | biostudies-literature

Templates are available to model nearly all complexes of structurally characterized proteins.

Project description:Traditional approaches to protein-protein docking sample the binding modes with no regard to similar experimentally determined structures (templates) of protein-protein complexes. Emerging template-based docking approaches utilize such similar complexes to determine the docking predictions. The docking problem assumes the knowledge of the participating proteins' structures. Thus, it provides the possibility of aligning the structures of the proteins and the template complexes. The progress in the development of template-based docking and the vast experience in template-based modeling of individual proteins show that, generally, such approaches are more reliable than the free modeling. The key aspect of this modeling paradigm is the availability of the templates. The current common perception is that due to the difficulties in experimental structure determination of protein-protein complexes, the pool of docking templates is insignificant, and thus a broad application of template-based docking is possible only at some future time. The results of our large scale, systematic study show that, surprisingly, in spite of the limited number of protein-protein complexes in the Protein Data Bank, docking templates can be found for complexes representing almost all the known protein-protein interactions, provided the components themselves have a known structure or can be homology-built. About one-third of the templates are of good quality when they are compared to experimental structures in test sets extracted from the Protein Data Bank and would be useful starting points in modeling the complexes. This finding dramatically expands our ability to model protein interactions, and has far-reaching implications for the protein docking field in general.

| S-EPMC3386081 | 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